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1
Černý, Vít. "Optimalizace geotechnického průzkumu a monitoringu při navrhování a provádění podzemních staveb." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-234559.
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The presented thesis focuses primarily on issues of geotechnical survey and geotechnical monitoring for underground line constructions. It deals with the current practice of geotechnical survey and monitoring. Based on the knowledge gained from specific buildings in the Czech Republic (Královopolské tunnels, tram tunnel Žabovřeská) and based on the author's practical local and foreign experience submits suggestions regarding their mutual optimization in order to improve outputs and reduce financial costs.
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Červenka, Jan. "Výpočet sedání výškové budovy s využitím metody konečných prvků." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409746.
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The focus of this thesis is to deal with reverse engineering of high-rise building settlements. This is modeled via the finite element method performed in the Plaxis 3D program. In the first part of this thesis, a calibration of input parameters of an appropriate material model – Hardening soil – is conducted. This calibration is a result of oedometric test data which were obtained within a geotechnical survey. An influence of soils over consolidation affecting calibration and the material model choice is described. Final values of reference stiffness parameters are used in a mathematical model of the focused area. This model is created for one half of the high-rise building plan, including vestibule. The high-rise building is founded in a foundation pit. The foundations of this building consist of raft foundation and piles of jet grouting. In the model, there are also changes in pore pressure during an excavation of foundation pit included. The functional model is used for parametric analyses, namely examining cases of object´s foundations and the possible influence of foundation pit´s symmetry on the object´s settlement. All the calculated processes in the object´s settlements are then compared to data obtained from geotechnical monitoring of the structure.
3
Wetterová, Alice. "Řešení stability svahu v náročných geotechnických podmínkách." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225706.
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Aim of the diploma thesis is design elements of slope stabilization in accordance with the planned highway D3 in Slovakia section of Cadca, Bukov - Svrčinovec and relocation of a local road. Objective subject is situated on the slopes of Cadca. In diploma thesis is an analysis of the area with the proposed stabilizing elements in the 5 GEO FEM, their assessment, including determining the overall stability of the territory according to the degree of safety.
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Ho, David Kar Hung. "Analyses of geotechnical construction by the finite element method." Thesis, University of Manchester, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277388.
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Koudela, Pavel. "Stanovení hodnot vstupních parametrů pokročilých materiálových modelů s využitím optimalizačních metod." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372248.
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Choice of the constitutive model and determination of input parameters are necessary for a successful application of numerical methods in geotechnical engineering. Higher complexity of modern constitutive models results in an increase of the number of input parameters and time requirements for their calibration. Optimization methods are a possible solution for this problem. An application in which metaheuristic optimization method Particle swarm optimization (PSO) is involved is presented in this thesis. Critical review and testing of various PSO alternatives was performed in the first part of this thesis. The most efective PSO alternatives were chosen. In the second part connection between PSO algorithm and finite element solver was prepared. Automatization of determination of constitutive models input parameters was performed on three boundary value problems: laboratory test (oedometer), in-situ test (pressuremeter) and geotechical construction (retaining wall). Three types of constitutive models are used. Linear elastic-perfectly plastic Mohr-Coulomb model, elastoplastic non-linear Hardening soil model and Hardening soil - small strain model.
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Bandara, Samila Sanjeevanie. "Material point method to simulate large deformation problems in fluid-saturated granular medium." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/283928.
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Serna, Marcelo Alejandro Llano. "Experimental and numerical study of geotechnical problems using the material point method." reponame:Repositório Institucional da UnB, 2016. http://repositorio.unb.br/handle/10482/22294.
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Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Programa de Pós-Graduação em Geotecnia, 2016.Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-11-24T15:02:37Z No. of bitstreams: 1 2016_MarceloAlejandroLlanoSerna.pdf: 4597920 bytes, checksum: d1815fd743fd8c6b5479aca9482e7686 (MD5)
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O objetivo deste trabalho é investigar os mecanismos de alguns problemas geotécnicos submetidos a grandes deformações, e mais especificamente o cone de penetração e escorregamentos na área de estabilidade de taludes. O fenômeno de grandes deformações em Geotecnia pode ser observado em problemas de ensaios de campo como SPT, CPT, DMT; ensaios de laboratório como o ensaio de cone e de palheta; em aplicações práticas como a cravação de estacas e em encostas após a ruptura de um talude. Uma das principais limitações na prática da engenharia geotécnica é que as formulações tradicionais para o cálculo de estruturas dependem da hipótese de pequenas deformações. Na última década, com o aumento da capacidade computacional e surgimento de novos métodos numéricos, tornou-se factível a modelagem numérica de problemas de grandes deformações, gerando a possibilidade de estudá-los em maior detalhe. Este trabalho centra-se na aplicação do Método do Ponto Material (MPM). O MPM é uma ferramenta numérica que adota um esquema de discretização Euleriano-Lagrangiano, o que fornece um esquema sofisticado para resolver o balanço de momento linear quando se observam grandes deformações. O método foi aplicado à análise de ensaios de penetração de cone em laboratório e a problemas reais de escorregamentos de taludes com grandes movimentos de massa. Inicialmente, foram feitos ensaios diretos e indiretos de resistência ao cisalhamento em amostras de caulim. O programa de ensaios de laboratório inclui o ensaio de palheta, ensaio de cone, ensaio de compressão oedométrica e ensaio de compressão triaxial convencional. Como produto dos ensaios de laboratório, foram propostas algumas relações entre parâmetros de estados críticos e o ensaio de queda de cone. Também baseado nos ensaios de laboratório, o programa NairnMPM foi testado e calibrado para resolver problemas geotécnicos simples como o ensaio de cone e o colapso de uma coluna de solo. Depois disso e com o intuito de verificar a capacidade do MPM para resolver problemas de grande escala, foram simulados os escorregamentos de taludes na barragem de Vajont, na Itália, e na rodovia Tokai-Hokuriku, no Japão. Finalmente, foi testado o processo de modelagem do escorregamento de Alto Verde, na Colômbia, e as variáveis dinâmicas previstas no modelo foram usadas no cálculo de risco. Os resultados se ajustaram muito bem às observações de campo, destacando a potencialidade do MPM como ferramenta prática na modelagem de vários problemas de grandes deformações na engenharia geotécnica.
The goal of this work is to investigate the mechanisms of various geotechnical problems subjected to finite strains, more specifically the fall cone test and run-out process during landslides. Large deformation phenomena may be observed in field testing such as SPT, CPT, DMT; laboratory testing such as fall cone test, mini-vane test, and practical problems such as pile driving and run-out process during landslides. The main limitations in the practice of geotechnical engineering are due to the fact that a wide number of design frameworks are based on the small strain hypothesis. In the last decade, with the increasing computational capacity and the development of novel numerical methods; solving large deformation models have become feasible. This fact allows studying in detail a wide number of phenomena in geotechnics. This work focuses on the application of the Material Point Method (MPM). The MPM is a numerical tool that adopts a Eulerian-Lagrangian scheme. Moreover, it allows a solid framework to solve the linear momentum balance when finite strains are observed. The method was used in the simulation of the fall cone test and real scale mass movements in landslides. Initially, direct and indirect shear strength measurements on kaolin clay were performed. The laboratory testing program included mini-vane shear test, fall cone test, oedometric compression, and conventional triaxial compression test. As a result of the laboratory testing, interesting relationships between the critical state parameters and the fall cone were established. Furthermore, NairnMPM open source code was tested and calibrated using the laboratory results to later solve simple geotechnical problems such as fall cone test and the collapse of a soil column. Afterwards, the possibility of simulating real-scale problems in landslides was addressed. The slope failure in Vajont, Italy, and Tokai-Hokuriku Expressway, Japan, were considered. Finally, the framework was tested in a landslide in Alto Verde, Colombia. The computed dynamic quantities were used in risk assessment of landslides. The results matched very well with field observations highlighting the potential of using MPM as a practical tool for modelling various problems involving large strains in geotechnical engineering.
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Sleiman, Maya. "2D Modelling of GeosyntheticallyReinforced Piled Embankments : Calibration Methods in PLAXIS 2D & Review of AnalyticalGuidelines." Thesis, KTH, Jord- och bergmekanik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-291424.
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This thesis focuses on the 2D modelling of Geosyntheticaly Reinforced Piled Embankments (GRPE) in PLAXIS 2D. In doing so, it explores two main aspects: 1) the calibration of Interface Stiffness Factors (ISFs) governing the soil-pile interaction of Embedded BeamRow (EBR) elements in PLAXIS 2D, and 2) the prospects and limitations of modelling geogrids (GR) in PLAXIS 2D when underlain by EBR elements; although several studies have validates the EBR element in modelling piles, none address the geogrid-EBR interaction and its implications on modelling GRPE systems. The thesis performs the calibration and validation processes using the full-scale GRPE structure ASIRI (Amélioration des Sols parInclusions Rigide) as documented in Briançon and Simon, 2012 and Nunez et al., 2013. Calibration of the EBR’s ISFs is done against 1) load-displacement curve of a test pile, 2)load-displacement of the structure’s monitored piles, and 3) differential soil-pile settlement. Model results for soil settlement, pile settlement, and pile load are then compared to reported values from the ASIRI site. Results show that the natural deviation between the structure and test pile’s load - displacement results in a wide range of possible calibration values for the ISFs, making calibration based on a test pile’s load-displacement curve an unpractical method. Even when such natural deviations were eliminated by calibrating the model against the structure’s reported values for pile load-displacement, model predictions for subsoil displacement were compromised. It is thus advisable to calibrate the EBR element with respect to soil settlement, pile settlement, and pile load rather than solely on a load-displacement curve as to avoid high divergences in soil-pile differential settlement. Modelling geogrids in GRPE systems, PLAXIS 2D underestimates GR strain due to its inability to simulate GR deflection: EBR elements are superimposed on top of a continuous soil mesh, thus allowing the embankment soil to settle through the EBR element. This unrealistically minimizes GR deflection, which underestimates GR strain when modelling GRPEs in PLAXIS 2D. In addition to validating the 2D modelling of GRPE systems, the thesis conducts a comparative literature review of GRPE design guidelines, focusing on the British BS8006 (2010), the German EBGEO (2011), and the Dutch CUR226 (2016). It then applies the latter two to the ASIRI full scale case study and compares results for predicted maximum GR strainand displacement to those from the PLAXIS 2D model and ASIRI measurements. The literature review shows that the geogrid load distribution is highly dependent on the state of subsoil support, where a uniform distribution is more appropriate for high subsoil support, and an inverse-triangular one more appropriate for low subsoil support. However, the analytical analysis of the ASIRI case shows that the triangular distribution, previously dismissed as unrealistic by the literature review, gives satisfactory results due to a combination of soil sliding and high subsoil support at the ASIRI site.Examensarbetet utvärderar 2D modellering av bankpålning med geosyntetisk armering (Geosyntheticallt Reinforced Piled Embankments – GRPE) i PLAXIS 2D. Examensarbetet utforskar två huvudaspekter: 1) kalibrering av Interface Stiffness Factors (ISFs) som styrjord-påle samspelet av Embedded Beam Row (EBR) element i PLAXIS 2D, och 2) möjligheter och begränsningar vid modellering av geonät i PLAXIS 2D när de ligger över EBR element. Även om flera studier har validerat användningen av EBR element för modelleringenav pålning, har inga behandlat samspelet geonät-EBR samt dess implikationer på modelleringen av GRPE. I arbetet har kalibrerings- och valideringsprocesser genomförts genom att använda den fullskaliga GRPE strukturen ASIRI (Amélioration des Sols par Inclusions Rigide) som dokumenterats i Briançon och Simon(2012) samt Nunez et al. (2013). Kalibrering av EBR ISFshar utförts mot: 1) last/förskjutningssamband av testpålar, 2) last/förskjutningssambad av övervakade pålar i strukturen, och 3) jord-påle differenssättningen. Modellens resultat försättningar i jorden, deformation i pålarna och lasten i pålarna jämförs med mätningar från ASIRI. Resultaten visar att naturliga avvikelser mellan strukturens- och testpålens last/förskjutningssambad resulterar i ett brett spektrum av möjliga kalibreringsvärden för ISFs, som gör kalibrering mot testpålens last/förskjutningssambad opraktisk. Även vid justering för detta genom kalibrering mot strukturpålens last/förskjutningssambad minskade modellens noggrannhet för sättningar i jorden. Det är således lämpligt att kalibrera EBR element motsättningar i jorden, deformation i pålarna och lasten i pålarna i stället för bara last/förskjutningssambaden för att undvika hög divergens i differenssättningen jord-påle. Vid modellering av GRPE-geonät underskattar PLAXIS 2D töjningen i geonäten på grund av sin oförmåga att simulera geonätens utböjning. EBR element ligger över ett kontinuerligt beräkningsnät av jord (soil mesh) som tillåter bankfyllningen att sätta genom EBRelement. Detta förhindrar utböjningen i geonätet som resulterar i en underskattning av töjningen i nätet vid modellering av GRPE i PLAXIS 2D. Förutom validering av 2D modelleringen av GRPE strukturer utför examensarbetet en jämförande literaturstudie av GRPE dimensioneringsriktlinjer med fokus på Brittisk BS8006 (2010), Tysk EBGEO (2011), och Nederländsk CUR226 (2016). De två sista nämnda riktlinjerna tillämpas på ASIRI för att prognosticera maximum geonättöjning och utböjning. Beräkningsresultat jämförs med värden från PLAXIS 2D modellen och mätningar från ASIRI. Litteraturstudien visar att geonätens belastningsfördelning är beroende främst på stödet från den underliggande jorden. Likformig belastningsfördelningen är lämpligare för en hög stödnivå och en invers-triangulär belastningsfördelningen för en låg stödnivå. Dock visar den analytiska analysen av ASIRI strukturen att en triangulär belastningsfördelning, som ansågs vara orealistisk i litteraturstudien, ger tillfredsställande resultat. Det är på grund av kombinationen av ’jordensglidning’ och hög stödnivå från den underliggandejorden i ASIRI:s fall.
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Herle, Ivo. "Ohde-Kolloquium 2014: Aktuelle Themen der Geotechnik." Technische Universität Dresden, 2014. https://tud.qucosa.de/id/qucosa%3A27847.
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Tagungsband des Ohde-Kolloquiums 2014. Die Fachtagung fand am 26.03.2014 an der TU Dresden statt.:Experimentelle Untersuchung der Kapillarität bei Sand unter monotoner und zyklischer Belastung, Marius Milatz
Mehrphasen-Modell zur Simulation von Suffosion, Heike Pfletschinger-Pfaff, Jan Kayser, Holger Steeb
Experimentelle Ermittlung intergranularer Kräfte unter Nutzung von 2D-DIC, Max Wiebicke, Edward Andò, Denis Caillerie, Gioacchino Viggiani
Systeme paralleler Scherbänder - Experimentelle und analytische Untersuchungen, Lars Röchter
Rechnerischer Stabilitätsnachweis für verflüssigungsgefährdete Standorte, Nándor Tamáskovics
Untersuchung des Einflusses von Gaseinschlüssen unterhalb des Grundwasserspiegels auf Druckausbreitung und Bodenverformungen mittels gekoppelter FE-Berechnungen, Hector Montenegro, Oliver Stelzer
Zeitabhängige Setzungen von Sand und FE-Simulationen einer Tagebaukippe, Stefan Vogt, Emanuel Birle, Gero Vinzelberg
Über die Berücksichtigung großer Bodendeformationen in numerischen Modellen, Daniel Aubram
Die Gefrierkernmethode - Weiterentwicklung des Erkundungsverfahrens zur geohydraulischen Charakterisierung von Sohlsedimenten, Daniel Straßer, Hermann-Josef Lensing, Dominik Richter, Simon Frank, Nico Goldscheider
Nutzung von Verfahren der Bildanalyse zur Baugrundbeurteilung, Markus Wacker, Thomas Neumann, Jens Engel, Gunter Gräfe
Anwendung von Elektroosmose zur Reduzierung des Herausziehwiderstandes von Spundwänden: Großmaßstäbliche Modellversuche in Ton, Christos Vrettos, Kai Merz
Zementfiltration bei der Herstellung von Verpressankern in nichtbindigen Böden, Xenia Stodieck, Thomas Benz
Modell- und Elementversuche zur Bodenverflüssigung, Erik Schwiteilo, Ivo Herle
Dynamische Probebelastung einer Mikropfahlgründung - Feldversuch und dynamische 3D-FE-Simulation mittels Hypoplastizität, Thomas Meier, Jens Jähnig, Sina Meybodi
Numerische und analytische Berechnungen zur Erdbebenbemessung von Böschungen, Hassan AlKayyal
10
Sleiman, Maya. "2D Modelling of Geosynthetically Reinforced Piled Embankments : Calibration Methods in PLAXIS 2D & Review of Analytical Guidelines." Thesis, KTH, Jord- och bergmekanik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-291424.
Full textAbstract:
This thesis focuses on the 2D modelling of Geosyntheticaly Reinforced Piled Embankments (GRPE) in PLAXIS 2D. In doing so, it explores two main aspects: 1) the calibration of Interface Stiffness Factors (ISFs) governing the soil-pile interaction of Embedded BeamRow (EBR) elements in PLAXIS 2D, and 2) the prospects and limitations of modelling geogrids (GR) in PLAXIS 2D when underlain by EBR elements; although several studies have validates the EBR element in modelling piles, none address the geogrid-EBR interaction and its implications on modelling GRPE systems. The thesis performs the calibration and validation processes using the full-scale GRPE structure ASIRI (Amélioration des Sols parInclusions Rigide) as documented in Briançon and Simon, 2012 and Nunez et al., 2013. Calibration of the EBR’s ISFs is done against 1) load-displacement curve of a test pile, 2)load-displacement of the structure’s monitored piles, and 3) differential soil-pile settlement. Model results for soil settlement, pile settlement, and pile load are then compared to reported values from the ASIRI site. Results show that the natural deviation between the structure and test pile’s load - displacement results in a wide range of possible calibration values for the ISFs, making calibration based on a test pile’s load-displacement curve an unpractical method. Even when such natural deviations were eliminated by calibrating the model against the structure’s reported values for pile load-displacement, model predictions for subsoil displacement were compromised. It is thus advisable to calibrate the EBR element with respect to soil settlement, pile settlement, and pile load rather than solely on a load-displacement curve as to avoid high divergences in soil-pile differential settlement. Modelling geogrids in GRPE systems, PLAXIS 2D underestimates GR strain due to its inability to simulate GR deflection: EBR elements are superimposed on top of a continuous soil mesh, thus allowing the embankment soil to settle through the EBR element. This unrealistically minimizes GR deflection, which underestimates GR strain when modelling GRPEs in PLAXIS 2D. In addition to validating the 2D modelling of GRPE systems, the thesis conducts a comparative literature review of GRPE design guidelines, focusing on the British BS8006 (2010), the German EBGEO (2011), and the Dutch CUR226 (2016). It then applies the latter two to the ASIRI full scale case study and compares results for predicted maximum GR strainand displacement to those from the PLAXIS 2D model and ASIRI measurements. The literature review shows that the geogrid load distribution is highly dependent on the state of subsoil support, where a uniform distribution is more appropriate for high subsoil support, and an inverse-triangular one more appropriate for low subsoil support. However, the analytical analysis of the ASIRI case shows that the triangular distribution, previously dismissed as unrealistic by the literature review, gives satisfactory results due to a combination of soil sliding and high subsoil support at the ASIRI site.Examensarbetet utvärderar 2D modellering av bankpålning med geosyntetisk armering (Geosyntheticallt Reinforced Piled Embankments – GRPE) i PLAXIS 2D. Examensarbetet utforskar två huvudaspekter: 1) kalibrering av Interface Stiffness Factors (ISFs) som styrjord-påle samspelet av Embedded Beam Row (EBR) element i PLAXIS 2D, och 2) möjligheter och begränsningar vid modellering av geonät i PLAXIS 2D när de ligger över EBR element. Även om flera studier har validerat användningen av EBR element för modelleringenav pålning, har inga behandlat samspelet geonät-EBR samt dess implikationer på modelleringen av GRPE. I arbetet har kalibrerings- och valideringsprocesser genomförts genom att använda den fullskaliga GRPE strukturen ASIRI (Amélioration des Sols par Inclusions Rigide) som dokumenterats i Briançon och Simon(2012) samt Nunez et al. (2013). Kalibrering av EBR ISFshar utförts mot: 1) last/förskjutningssamband av testpålar, 2) last/förskjutningssambad av övervakade pålar i strukturen, och 3) jord-påle differenssättningen. Modellens resultat försättningar i jorden, deformation i pålarna och lasten i pålarna jämförs med mätningar från ASIRI. Resultaten visar att naturliga avvikelser mellan strukturens- och testpålens last/förskjutningssambad resulterar i ett brett spektrum av möjliga kalibreringsvärden för ISFs, som gör kalibrering mot testpålens last/förskjutningssambad opraktisk. Även vid justering för detta genom kalibrering mot strukturpålens last/förskjutningssambad minskade modellens noggrannhet för sättningar i jorden. Det är således lämpligt att kalibrera EBR element motsättningar i jorden, deformation i pålarna och lasten i pålarna i stället för bara last/förskjutningssambaden för att undvika hög divergens i differenssättningen jord-påle. Vid modellering av GRPE-geonät underskattar PLAXIS 2D töjningen i geonäten på grund av sin oförmåga att simulera geonätens utböjning. EBR element ligger över ett kontinuerligt beräkningsnät av jord (soil mesh) som tillåter bankfyllningen att sätta genom EBRelement. Detta förhindrar utböjningen i geonätet som resulterar i en underskattning av töjningen i nätet vid modellering av GRPE i PLAXIS 2D. Förutom validering av 2D modelleringen av GRPE strukturer utför examensarbetet en jämförande literaturstudie av GRPE dimensioneringsriktlinjer med fokus på Brittisk BS8006 (2010), Tysk EBGEO (2011), och Nederländsk CUR226 (2016). De två sista nämnda riktlinjerna tillämpas på ASIRI för att prognosticera maximum geonättöjning och utböjning. Beräkningsresultat jämförs med värden från PLAXIS 2D modellen och mätningar från ASIRI. Litteraturstudien visar att geonätens belastningsfördelning är beroende främst på stödet från den underliggande jorden. Likformig belastningsfördelningen är lämpligare för en hög stödnivå och en invers-triangulär belastningsfördelningen för en låg stödnivå. Dock visar den analytiska analysen av ASIRI strukturen att en triangulär belastningsfördelning, som ansågs vara orealistisk i litteraturstudien, ger tillfredsställande resultat. Det är på grund av kombinationen av ’jordensglidning’ och hög stödnivå från den underliggandejorden i ASIRI:s fall.
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Santos, Rodríguez Cristian de. "Backanalysis methodology based on multiple optimization techniques for geotechnical problems." Doctoral thesis, Universitat Politècnica de Catalunya, 2015. http://hdl.handle.net/10803/334179.
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Nowadays, thanks to the increase of computers capability to solve huge and complex problems, and also thanks to the endless effort of the geotechnical community to define better and more sophisticated constitutive models, the challenge to predict and simulate soil behavior has been eased. However, due to the increase in that sophistication, the number of parameters that define the problem has also increased. Moreover, frequently, some of those parameters do not have a real geotechnical meaning as they just come from mathematical expressions, which makes them difficult to identify. As a consequence, more effort has to be placed on parameters identification in order to fully define the problem.
This thesis aims to provide a methodology to facilitate the identification of parameters of soil constitutive models by backanalysis. The best parameters are defines as those that minimize an objective function based on the differences between measurements and computed values. Different optimization techniques have been used in this study, from the most traditional ones, such as the gradient based methods, to the newest ones, such as adaptive genetic algorithms and hybrid methods. From this study, several recommendations have been put forward in order to take the most advantage of each type of optimization technique. Along with that, an extensive analysis has been carried out to determine the influence on soil parameters identification of what to measure, where to measure and when to measure in the context of tunneling. The Finite Element code Plaxis has been used as a tool for the direct analysis. A FORTRAN code has been developed to automate the entire backanalysis procedure. The Hardening Soil Model (HSM) has been adopted to simulate the soil behavior. Several soil parameters of the HSM implemented in Plaxis, such as E_50^ref, E_ur^ref, c and f, have been identified for different geotechnical scenarios. First, a synthetic tunnel case study has been used to analyze all the different approaches that have been proposed in this thesis. Then, two complex real cases of a tunnel construction (Barcelona Metro Line 9) and a large excavation (Girona High-Speed Railway Station) have been presented to illustrate the potential of the methodology. Special focus on the influence of construction procedures and instruments error structure has been placed for the tunnel backanalysis, whereas in the station backanalysis, more effort has been devoted to the potential of the concept of adaptive design by backanalysis. Moreover, another real case, involving a less conventional geotechnical problem, such as Mars surface exploratory rovers, has been also presented to test the backanalysis methodology and the reliability of the Wong & Reece wheel-terrain model; widely adopted by the terramechanics community, but nonetheless, still not fully accepted when analyzing lightweight rovers as the ones that have been used in recent Mars exploratory missions.Actualmente, gracias al aumento de la capacidad de los ordenadores para resolver problemas grandes y complejos, y gracias también al gran esfuerzo de la comunidad geotécnica de definir mejores y más sofisticados modelos constitutivos, se ha abordado el reto de predecir y simular el comportamiento del terreno. Sin embargo, debido al aumento de esa sofisticación, también ha aumentado el número de parámetros que definen el problema. Además, frecuentemente, muchos de esos parámetros no tienen un sentido geotécnico real dado que vienen directamente de expresiones puramente matemáticas, lo cual dificulta su identificación. Como consecuencia, es necesario un mayor esfuerzo en la identificación de los parámetros para poder definir apropiadamente el problema. Esta tesis pretende proporcionar una metodología que facilite la identificación mediante el análisis inverso de los parámetros de modelos constitutivos del terreno. Los mejores parámetros se definen como aquellos que minimizan una función objetivo basada en la diferencia entre medidas y valores calculados. Diferentes técnicas de optimización han sido utilizadas en este estudio, desde las más tradicionales, como los métodos basados en el gradiente, hasta las más modernas, como los algoritmos genéticos adaptativos y los métodos híbridos. De este estudio, se han extraído varias recomendaciones para sacar el mayor provecho de cada una de las técnicas de optimización. Además, se ha llevado a cabo un análisis extensivo para determinar la influencia sobre qué medir, dónde medir y cuándo medir en el contexto de la excavación de un túnel. El código de Elementos Finitos Plaxis ha sido utilizado como herramienta de cálculo del problema directo. El desarrollo de un código FORTRAN ha sido necesario para automatizar todo el procedimiento de Análisis Inverso. El modelo constitutivo de Hardening Soil ha sido adoptado para simular el comportamiento del terreno. Varios parámetros del modelo constitutivo de Hardening implementado en Plaxis, como E_50^ref, E_ur^ref, c y f, han sido identificados para diferentes escenarios geotécnicos. Primero, se ha utilizado un caso sintético de un túnel donde se han analizado todas las distintas técnicas que han sido propuestas en esta tesis. Después, dos casos reales complejos de una construcción de un túnel (Línea 9 del Metro de Barcelona) y una gran excavación (Estación de Girona del Tren de Alta Velocidad) se han presentado para ilustrar el potencial de la metodología. Un enfoque especial en la influencia del procedimiento constructivo y la estructura del error de las medidas se le ha dado al análisis inverso del túnel, mientras que en el análisis inverso de la estación el esfuerzo se ha centrado más en el concepto del diseño adaptativo mediante el análisis inverso. Además, otro caso real, algo menos convencional en términos geotécnicos, como es la exploración de la superficie de Marte mediante robots, ha sido presentado para examinar la metodología y la fiabilidad del modelo de interacción suelo-rueda de Wong y Reece; extensamente adoptado por la comunidad que trabajo en Terramecánica, pero aún no totalmente aceptada para robots ligeros como los que se han utilizado recientemente en las misiones de exploración de Marte.
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McKay, Sara E. "Geotechnical analysis of horizontal drains as a landslide mitigation method in western Washington /." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1437660.
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Thesis (M.S.)--University of Nevada, Reno, 2006."August, 2006." Includes bibliographical references (leaves 93-97). Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2006]. 1 microfilm reel ; 35 mm. Online version available on the World Wide Web.
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Bhamidipati, Raghava A. "Use Of Laboratory Geophysical And Geotechnical Investigation Methods To Characterize Gypsum Rich Soils." UKnowledge, 2016. http://uknowledge.uky.edu/ce_etds/45.
Full textAbstract:
Gypsum rich soils are found in many parts of the world, particularly in arid and semi-arid regions. Most gypsum occurs in the form of evaporites, which are minerals that precipitate out of water due to a high rate of evaporation and a high mineral concentration. Gypsum rich soils make good foundation material under dry conditions but pose major engineering hazards when exposed to water. Gypsum acts as a weak cementing material and has a moderate solubility of about 2.5 g/liter. The dissolution of gypsum causes the soils to undergo unpredictable collapse settlement leading to severe structural damages. The damages incur heavy financial losses every year.
The objective of this research was to use geophysical methods such as free-free resonant column testing and electrical resistivity testing to characterize gypsum rich soils based on the shear wave velocity and electrical resistivity values. The geophysical testing methods could provide quick, non-intrusive and cost-effective methodologies to screen sites known to contain gypsum deposits. Reconstituted specimens of ground gypsum and quartz sand were prepared in the laboratory with varying amounts of gypsum and tested. Additionally geotechnical tests such as direct shear strength tests and consolidation tests were conducted to estimate the shear strength parameters (drained friction angle and cohesion) and the collapse potential of the soils.
The effect of gypsum content on the geophysical and geotechnical parameters of soil was of particular interest. It was found that gypsum content had an influence on the shear wave velocity but had minimal effect on electrical resistivity. The collapsibility and friction angle of the soil increased with increase in gypsum. The information derived from the geophysical and geotechnical tests was used to develop statistical design equations and correlations to estimate gypsum content and soil collapse potential.
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Bůžková, Eliška. "Zajištění sanační jámy pro ekologické účely." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225487.
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As the trend in environmental care grows, the emphasis on removing the old environmental burdens is bigger. This thesis is dedicated to the case when the soil was contaminated by products of gas industry in the area of Jihomoravská plynárenská, a.s. in Brno - Zábrdovice . The aim of this work is to select the appropriate remediation technology and shoring remediation pit in mentioned locality. Diploma thesis also includes design and assessment of selected construction sheeting calculated by the method of dependent pressures, technology design and implementation of construction drawings.
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Johansson, Erik. "Metodik för kvantifiering av läckage genom fyllningsdammar." Thesis, Luleå tekniska universitet, Byggkonstruktion och -produktion, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68553.
Full textAbstract:
Fyllningsdammar har ett naturligt läckage genom dammen på grund av dess uppbyggnad av jord- och stenmaterial som har en viss genomsläpplighet. I RIDAS finns krav att läckaget skall övervakas nedströms fyllningsdammar för att upptäcka långsamtgående förändringar av läckagets storlek. Läckagemätningar vid fyllningsdammar registrerar inte endast läckaget genom dammen utan påverkas av yttre faktorer såsom nederbörd och sprickor i berggrunden. Vidare kan nederbördsregistreringar ha osäkerheter som gör att den sanna nederbörden inte mäts. Syftet med detta examensarbete är att studera och kvantifiera hur de yttre faktorerna påverkar läckagemätningar vid fyllningsdammar. En fallstudie med inpumpningsförsök har utförts för att bedöma hur ett simulerat läckage påverkar mätöverfall M6 och M7 vid en svensk dammanläggning. Ett annat syfte med inpumpningsförsöken var att utreda nederbördens avrinningsväg samt att upptäcka förluster av läckagevatten på sin väg till mätöverfallen. Inpumpningsförsöken begränsades till två punkter i terrängen nedströms den studerade dammen där vatten pumpades ut i terrängen. Nederbörden som studeras avser endast regn och vid analys begränsas utvärdering mellan läckagemätningar och de yttre faktorernas påverkan till inhämtad indata under inpumpningsförsöken. Det ena inpumpningsförsöket påverkades av pågående snösmältning vilket påverkade resultaten negativt. Resultaten från det andra inpumpningsförsöket tyder på att inhämtad indata från nederbördsregistrering behöver korrigeras med hänsyn till vindförluster samt att de automatiska givarna i mätöverfall M6 och M7 mäter fel. Vid jämförelse mellan nederbörd, inpumpat vatten och läckage genom dammen mot registrerat vatten i mätöverfall M6 registreras 57 procent av det mängden vatten i mätöverfallet. När hänsyn tas till vindförluster, evapotranspiration samt att det registrerade flödet räknas om efter manuella mätningar av vattenhöjden över mätöverfallet har mätöverfallet registrerat 86 procent av mängden vatten. Detta ger en indikation på betydelsen av att korrigera indata för nederbördsregistreringen samt att givarens felmarginaler i mätöverfallen är av betydande storlek. Denna studie indikerar på för stora felmarginaler vid flödesregistreringen för mätöverfall M6 och M7 vilket begränsar förmågan att dra slutsatser om hur och i vilken utsträckning de yttre faktorerna påverkar mätöverfallen. Metoden med inpumpningsförsök bedöms vara en bra metod för att utvärdera hur nederbörd påverkar läckagemätningar på utvalda områden i terrängen samt för att försöka hitta förluster av läckagevatten genom dammen. Det bedöms även vara en bra metod för att funktionskontrollera läckagemätningar samt att tillföra en kontrollerad förändring i mätningssystemen som går att mäta och utvärdera. I sin helhet bedöms det vara bättre att jämföra redan registrerad nederbörd mot responsen i mätöverfallen för att försöka förstå i vilken utsträckning nederbörd påverkar läckagemätningar vid fyllningsdammar.Embankment dams have natural seepage through the dam due to the construction of soil and rock materials. RIDAS demands seepage control in embankment dams to find and evaluate slow changes of the seepage. The seepage control measurements do not only measure the seepage through the dam but is also affected by external factors such as rainfall or cracks in the bedrock. The rainfall is also almost never measured correctly due to three main errors in the way it is measured. The purpose of this master thesis is to study and quantify how external factors affect the seepage control in embankment dams. A case study in a Swedish dam was conducted where water was pumped into the terrain on the downstream side of the dam. This was done in order to evaluate how a sequence of rainfall affects the seepage control measurements in embankment dams in general. Another purpose with pumping water into the terrain was to evaluate the size of the basin where rainfall affects the seepage control measurements and also to track down if and where there are any loss of seepage before it is being measured. Water was being pumped at two different locations on the downstream side of the dam and the evaluation of seepage control measurements and the outer factors affecting the measurements was limited to input parameters collected during the time where water was being pumped into the terrain. The first time water was being pumped into the terrain the seepage control measurements were affected by snow still melting and being registered which affected the results negatively. The second time water was being pumped into the terrain the results suggests that rainfall measurements needs to be corrected with respect to wind losses and that the seepage control measurements in the Swedish dam are not completely reliable. When a comparison between the registered rainfall, the amount of water being pumped in the terrain and the natural seepage through the dam compared to the amount of water being measured it was found that only 57 percent of the water was being measured. Later on when regards were taken to evapotranspiration, wind losses and the seepage measurements were recalculated from manual measurements of the water height it was found that 86 percent of the water was being measured. This indicates that it can be necessary and meaningful to correct the input data from rainfall measurements and seepage measurements in order to get more credible results. This study indicates that the margins of errors in the seepage control measurements are too big which limits the ability to draw conclusions on how and to which extent the outer factors affect the seepage control measurements. The method where water is being pumped into the terrain is concluded to be a good way to evaluate how rainfall affects the seepage control measurements on selected parts of the terrain and also to detect where and if there are any losses of seepage before it is being measured. It is also concluded to be a good method for testing the functioning of the seepage control measurements and allows for a controlled disturbance of the system where the systems response can directly be measured. In order to evaluate to which extent the rainfall affects the seepage control measurements it is estimated to be better to compare a sequence of rainfall to the direct response from the seepage control measurements.
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Holmström, Robin, and Dmytro Yakubov. "Evaluation of future trial embankments : A study of measurement methods to apply on Lampen test embankments, Kalix, Sweden." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-62824.
Full textAbstract:
At the Lampen site outside of Kalix, Sweden two embankments with heights 1,5m and 2m have been built to study and test the properties of sulfide soil that is located in the Gulf of Bothnia coastal areas. In this master thesis investigations have been done on what more could be done at the Lampen site today concerning new technics, measurements, observations and calculations etc. rather than building new embankments. Conclusions have been drawn from a total of 7 cases including Lampen what more could be done at the Lampen site. Verifications have also been done on the work made at the different cases. It was concluded that the work on all the different cases could be verified in some way against hand calculations or PLAXIS models beside the Murro test embankment site because this work had too little release data aterial given. Made verifications gave corresponding results to the described and measured ones in the real cases. Cases that have been looked at are: Murro test embankment (Karstunen et.al, 2005) Test embankment constructed to failure on soft marine clay in Malaysia (Brand, 1991) Test embankment on hydraulically placed PFA (Pulverized Fuel Ashes) in the United Kingdom (Cousens, et al., 2003) Trial Embankment on peat in Booneschans the Netherlands (Zwanenburg, et al., 2012) A case study on sulphide soil on road of E12 north link, Västerslätt, Umeå, Sweden (Törnqvist, 2013) Follow up and evaluation of settlements on the road 760 in Norrbotten, Sweden (Johansson, 2010) Test Embankments Lampen, Sweden (Andersson, 2012) From these cases it was concluded that more calculations in Plaxis 2D, Plaxis 3D and maybe Geosuite settlements software programs should be done at the Lampen site, both for long term and short term behavior and settlements as the only current model made is an Embacko V1.02 which is based on the work and results by Andersson (2012). Also verifications should be made by hand calculations on the models as this had not been done until today. Further disturbed samples should have been taken at the Lampen site as it have been done at the Murro site in Finland as this site is built on similar ground conditions with sulfide soil. Heavy equipment used at the site and as well the building of the embankments might have disturb or influenced the soil so the properties might have been changed. Also a couple of new measurement technics have been looked at for Lampen. The looked at technics are optics fibers, drones and ShapeAccelArray (SAA). ShapeAccelArray (SAA) devices could be installed at some different points on the site, down through the soil profile to give better readings on vibrations, accelerations, deformations and settlements. A drone could also be used during the snow free period to fly daily-predefined paths and make a 3D mapping of the geotechnical structures. And if the embankments would be built now again from the start it would be a good idea to install from the start a smart geotextile with polymer optical fibers (POF) totally covering the whole embankment size. This would give continues reading on deformations and displacements. But since the measurements and all other work at the Lampen site in the project went well and gave good results there is no need to do further changes.
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Zhou, Hongjie. "Numerical study of geotechnical penetration problems for offshore applications." University of Western Australia. Centre for Offshore Foundation Systems, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0239.
Full textAbstract:
The research carried out in this thesis has concentrated on the application of numerical solutions to geotechnical penetration problems in offshore engineering. Several important issues closely relevant to deep-water oil and gas developments were investigated, covering installation of suction caisson foundations, interpretation of fullflow penetrometers and shallow penetration of a cylindrical object (submarine pipeline or T-bar), all in clayey sediments such as are often encountered in deep-water sites. These problems are commonly characterised by large vertical movements of structural elements relative to the seabed. A large deformation finite element method was adopted and further developed to simulate these challenging problems, referred to as Remeshing and Interpolation Technique with Small Strain. In this approach, a sequence of small strain Lagrangian increments, remeshing and interpolation of stresses and material properties are repeated until the required displacement has been reached. This technique is able to model relative motion between the penetrating objects and the soil, which is critical for evaluating soil heave inside the caissons, the effect of penetration-induced remoulding on the resistance of full-flow penetrometers, and influence of soil surface heave on the embedment of pipelines. '...' Simple expressions were presented allowing the resistance factors for the T-bar and ball penetrometers to be expressed as a function of the rate and strain-softening parameters. By considering average strength conditions during penetration and extraction of these full-flow penetrometers, an approximate expression was derived that allowed estimation of the hypothetical resistance factor with no strain-softening, and hence an initial estimate of the stain-rate dependency of the soil. Further simulations of cyclic penetration tests showed that a cyclic range of three diameters of the penetrometers was sufficient to avoid overlap of the failure mechanism at the extremes and mid-point of the cyclic range. The ball had higher resistance factors compared with the T-bar, but with similar cyclic resistance degradation curves, which could be fitted accurately by simple expressions consistent with the strain-softening soil model adopted. Based on the curve fitting, more accurate equations were proposed to deduce the resistance factor with no strain-softening, compared with that suggested previously based on the resistances measured in the first cycle of penetration and extraction. The strain-rate dependency was similar in intact or post-cyclic soil for a given rate parameter. The resistance factor for the post-cyclic condition was higher than that for the initial conditions, to some degree depending upon soil sensitivity and brittleness parameter. For the shallow penetration of a cylindrical object, the penetration resistance profile observed from centrifuge model tests was very well captured by the numerical simulation. The mechanism of shear band shedding was reproduced by the numerical technique, although the frequency of the shear band generation and the exact shape of the heave profile were not correctly captured, which were limited by the simple strainsoftening soil model adopted.
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Bertel, Jeffrey D. "Analytical study of the spectral-analysis-of-surface-waves method at complex geotechnical sites." Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4625.
Full textAbstract:
Thesis (M.S.) University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 21, 2007) Includes bibliographical references.
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Javakhishvili, Zurab. "The coupled finite-boundary element method applied to the analysis of geotechnical engineering problems." Thesis, London South Bank University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261020.
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Yan, Li. "Hydraulic gradient similitude method for geotechnical modelling tests with emphasis on laterally loaded piles." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/31899.
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A study has been undertaken to evaluate and apply the hydraulic gradient similitude
method to geotechnical model testings. This method employs a high hydraulic gradient across granular soils to effectively increase self-weight stresses in the model. Testing principle and procedures are presented, and the factors affecting test results discussed. An apparatus (UBC-HGST) using this testing principle has been developed.
Three applications are presented in which the hydraulic gradient similitude method is evaluated, and the existing concepts and methods of analysis for the problems
studied are examined.
In the footing tests, it is found that the scaling laws implied in the hydraulic gradient
modelling test are satisfied, and are similar to those of the centrifuge modelling technique. Load-settlement curves are found to be similar to those in centrifuge tests. The test results illustrate the importance of the stress level in the load-settlement responses.
Terzaghi's bearing capacity formula is compared with the observed bearing capacities under different stress levels. It is found that due to the stress level effects,
the bearing capacity coefficient, Nγ, decreases linearly with footing width on the log-log scale which is in accordance with other model study and analytical results.
In the downhole and crosshole seismic tests, results are used to evaluate the empirical
equations that relate shear wave velocity and soil stresses in terms of field stress condition. It is found that although the various equations can predict the insitu shear wave velocity profile reasonably well, only the equation which is based on the significant
stresses in the wave propagation and particle motion directions can predict the variation of velocity ratio between the downhole and SH crosshole tests. It is also found that the stress ratio has some effects on the downhole (or SV crosshole) tests,
but not on the SH crosshole tests. This indicates that only the stress ratio in the plane of wave propagation is important to the shear wave velocity. Comparison between
the downhole and SH crosshole tests shows that the structure anisotropy was about 10% in terms of shear wave velocity. Prediction of Ko values using shear wave measurement is evaluated, and its practical difficulties are addressed.
In the laterally loaded pile tests, the pile response to static and cyclic loadings at various stress levels controlled by the hydraulic gradients is examined in terms of pile head response, pile bending moment and soil-pile interaction P-y curves. For the static loading, pile head response and bending moment are found to be significantly affected by the soil-pile relative stiffness, pile diameter, loading condition and pile head fixity. However, little effects of loading eccentricity and pile head fixity are found on the P-y curves. While pile diameter is found to have effects on the P-y curves at large pile deflection, its effects are negligible at small deflecton range. The effects of relative soil-pile stiffness on the P-y curves due to stress levels can be normalized by the soil modulus and pile diameter for the curves below 1 pile diameter, as computed by the plane strain finite element analysis. Two methods of generating P-y curves are suggested, and found to give satisfactory results as compared with the test data and the prediction given by API code (1987). For cyclic loading, different pile responses are observed in "one-way" as compared to "two-way" cyclic loading. The cyclic P-y curves are derived, and found to be highly nonlinear and hysteretic, and change with number of loading cycles. From these studies, it is shown that the hydraulic gradient similitude method provides a simple and inexpensive means of model testing for many geotechnical engineering problems and adds to the data base from which methods of analysis can be evaluated.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Kane, William F. "Geologic and geotechnical controls on the stability of coal mine entries." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/64668.
Full textAbstract:
Roof and rib failures in underground coal mines are one of the major problems facing the industry today. In addition to safety considerations, the resulting economic impact of such failures is staggering. Uncovering and replacing buried and damaged equipment and clearing entries can account for a large expenditure in lost man-hours and machinery. Yet, because of the complex nature of their formation, geological variability, and structural characteristics, coal mine roof strata are one of the least controllable of all mine design parameters. This is especially true along the leading (southeastern) edge of the Appalachian coalfields where considerable faulting and movement have contributed to hazardous coal mining roof conditions.
For this research, a detailed study of several mines, in the southern Appalachian coalfields, was undertaken to determine the most prominent geomechanical factors affecting roof stability and to evaluate their influence in promoting unstable ground conditions. In order to accomplish this task, the major geological and geomechanical features found to be detrimental to the coal mine roof within the Appalachian basin were identified and mapped in four Virginia mines.
Statistical processing by chi-square and linear regression analysis as well as analytical analysis by the finite element method were used to determine the influence of geology, mine-layout, and support methods on roof stability. It was found that some easily determined parameters can be successfully used to predict potentially unstable areas. A simplified roof classification system was developed based on the geomechanical parameters, which can be used to assess the stability of a particular roof type. A Roof Rating Index was also devised capable of expressing the probability of failure under a given set of geomechanical conditions.Ph. D.
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Kang, GiChun. "Assessing uplift displacement of buried geotechnical structures in liquefied ground during earthquakes." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120829.
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Salehian, Ali. "PREDICTING THE DYNAMIC BEHAVIOR OF COAL MINE TAILINGS USING STATE-OF-PRACTICE GEOTECHNICAL FIELD METHODS." UKnowledge, 2013. http://uknowledge.uky.edu/ce_etds/9.
Full textAbstract:
This study is focused on developing a method to predict the dynamic behavior of mine tailings dams under earthquake loading. Tailings dams are a by-product of coal mining and processing activities. Mine tailings impoundments are prone to instability and failure under seismic loading as a result of the mechanical behavior of the tailings. Due to the existence of potential seismic sources in close proximity to the coal mining regions in the United States, it is necessary to assess the post-earthquake stability of these tailings dams.
To develop the aforementioned methodology, 34 cyclic triaxial tests along with vane shear tests were performed on undisturbed mine tailings specimens from two impoundments in Kentucky. Therefore, the liquefaction resistance and the residual shear strength of the specimens were measured. The laboratory cyclic strength curves for the coal mine specimens were produced, and the relationship between plasticity, density, cyclic stress ratio, and number of cycles to liquefaction were identified.
The samples from the Big Branch impoundment were generally loose samples, while the Abner Fork specimens were dense samples, older and slightly cemented. The data suggest that the number of loading cycles required to initiate liquefaction in mine tailings, NL, decreases with increasing CSR and with decreasing density. This trend is similar to what is typically observed in soil. For a number of selected specimens, using the results of a series of small-strain cyclic triaxial tests, the shear modulus reduction curves and damping ratio plots were created.
The data obtained from laboratory experiments were correlated to the previously recorded geotechnical field data from the two impoundments. The field parameters including the SPT blow counts (N1)60, corrected CPT cone tip resistance (qt), and shear wave velocity (vs), were correlated to the laboratory measured cyclic resistance ratio (CRR). The results indicate that in general, the higher the (N1)60 and the tip resistance (qt), the higher the CSR was.
Ultimately, practitioners will be able to use these correlations along with common state-of-practice geotechnical field methods to predict cyclic resistance in fine tailings to assess the liquefaction potential and post-earthquake stability of the impoundment structures.
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Katsigiannis, Georgios. "Modern geotechnical codes of practice and new design challenges using numerical methods for supported excavations." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/10037673/.
Full textAbstract:
Eurocode 7 (EC7), which is the geotechnical engineering design standard in Europe, introduces the concept of partial safety factors and distinguishes between Serviceability Limit State (SLS) and Ultimate Limit State (ULS). While EC7 allows the use of Finite Element Methods (FEM) for ULS, there is limited guidance in a number of issues. The thesis focuses on a number of constitutive models of increasing complexity and both the characteristic and design values of the model parameters are derived for the London Clay and a soft Marine clay. The challenges associated with factoring the undrained shear strength when using total and effective stress parameters are discussed. The use of FEM for ULS design of supported excavations, is highlighted using simple excavation examples and two deep excavation case histories; the Moorgate Crossrail Station and the Exhibition Road Building of the Victoria & Albert Museum. The different factoring combinations and strategies, required by EC7, are compared in terms of the calculated design internal structural forces, illustrating that the use of more advanced models can have significant advantages. Moreover, comparisons are made between the design prop loads calculated from the FEM and a number of empirical methods. The HYD limit state, as described in EC7, relates to the upward flow of water through the soil towards a free surface. The HYD verification, using FEM, can be performed with two approaches; the soil block approach by calculating the equilibrium of a rectangular soil block and the integration point approach by checking that the equilibrium is satisfied at each integration point. Thorough comparisons between the two approaches using benchmark geometries illustrate the benefits of using more advanced approaches for such stability verifications.
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Wendlandt, Nichole Jean. "A Geotechnical Evaluation of the Launched Soil-Nailing Method of Landslide Stabilization in Summit County, Ohio." Kent State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=kent1239813377.
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Granskär, Joakim. "Evaluation of SCPT-surveys as method for accessing dynamic modulus." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68756.
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The purpose of this master thesis is to evaluate the results from the completed SCPT (Seismic Cone Penetration Test) surveys with respect to the methods ability to estimate dynamic young´s modulus. This has been done by comparing the result from SCPT to other seismic methods and dynamic parameters converted from “static” geotechnical surveys. SCPT is a relatively new method which has not been used by Sweco or in Sweden to any greater extent and is therefore of interest to be looked in to. By adding two geophones to an ordinary CPT (Cone Penetration Test) equipment as well as including strike plates, hammer and logger system one can log dynamic parameters in addition to the regular parameters logged by a CPT system. This is done by stopping the otherwise continuous CPT survey every meter and striking the strike plates, which are placed under the tracks of the drilling rig. Seismic waves will then travel through the soil down to the geophones and be used to calculate dynamic parameters. For this master thesis a total of 47 geotechnical and geophysical surveys have been considered. The location of these 47 are approximately 7 km north of Norrköping and have been conducted between the years 2016-2017 for the East Link Project. The geotechnical surveys are composed of weight-sounding, ram-sounding and CPT while the geophysical ones are SCPT, refraction-survey and MASW (Multichannel Analysis of Surface Waves). Static elastic parameters have been calculated using the geotechnical survey results according to the Swedish transportation administrations standardized methods. These have then been converted to dynamic parameters with the help of different relationships. When these have been converted they can be compared to SCPT results and other seismic survey methods which also use wave velocity, Poisson’s ratio and density to calculate dynamic elastic parameters. Based on the results from this thesis it can be concluded that the seismic test add-on to a standard CPTu survey is a good method for accessing dynamic modules and it gives extended information of the soil stratigraphy from one single survey point. After the studies and analyses conducted for this thesis it can be concluded that the proposed conversion between static and dynamic young’s modulus using the Alpan curve gives slightly higher values than the ones derived directly from shear waves using SCPT. The other conversion using cone tip resistance to shear wave velocity gives on the other hand slightly lower values than the ones measured with the SCPT. The analysis also indicate similar trends in results between the different seismic methods. These results does however also shows that the used assumptions are somewhat general for accurate comparisons between the methods.
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GUTIERREZ, LUCAS LUDEÑA. "FORMULATION AND SOME APPLICATIONS OF MATERIAL POINT METHOD IN GEOTECHNICAL PROBLEMS IN STATIC AND DYNAMIC CONDITIONS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2016. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=33844@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
Em problemas geotécnicos podem ocorrer grandes deformações devido a chuvas prolongadas, sismos, deslizamentos de encostas, etc. Material point method (MPM) é um método de solução baseado no Método dos Elementos Finitos (MEF) que oferece vantagens para o cálculo estático e dinâmico que envolve deformações desse tipo. O objetivo desta dissertação é utilizar o MPM em problemas geotécnicos em condições estáticas e dinâmicas. Esta pesquisa mostra o procedimento de analises do MPM para a condição não acoplada (só solido sem presença de água) e depois acoplada. Para a revisão matemática de MPM se faz antes um resumo da teoria do MEF na metodologia de conservação de quantidade de movimento. Nestas duas formas de resolver os problemas geotécnicos foram expostos três exemplos simples. O primeiro é uma coluna de solo simulado sob os fundamentos da elasticidade, com o objetivo de verificar o deslocamento vertical pelo peso próprio. Isto foi resolvido mediante quatro diferentes métodos: analítica, MEF por resíduos ponderados, MEF por conservação de quantidade de movimento, e MPM. Todos eles consideram somente a fase solida. No segundo exemplo, tem-se solo na geometria de quadrado de lado 1 metro, onde busca-se obter as poropressões quando atingir a condição permanente enquanto os deslocamentos ocorrem ao longo do tempo; ou seja, a análise é acoplada e é resolvida pelo método MPM. Para uma aplicação mais realista, foi feita a análise (não acoplada) da barragem Palo Redondo, pertencente ao projeto Chavimochic, localizada na região de La Libertad, Perú. Nesta análise dinâmica considerou-se dois modelos constitutivos: Elástico e Mohr Coulomb, além de um sismo.
In geotechnical problems can happen large strains because of prolonged rains, earthquake, slide slope, etc. Material point method is a solution method based on the finite element method (FEM) which offers advantages for static and dynamic calculation that involve that kind of strains. The objective in this dissertation is to use the MPM in geotechnical problems in statics and dynamics conditions. This research shows the analysis procedure of MPM for uncoupled condition (only solids, without water) and then coupled. Before the mathematical theory of MPM, a review of the theory of FEM in the conservation of quantidade de movimento is done. In this two methodology were raised three examples. The first one is a soil column that was modeled elastically, in which the main objective in to analyze the vertical displacement because of own weight. This was solved by four different methods: analytically, FEM weighted residual, FEM conservation of momentum, and MPM. All of them consider only the solid phase. The second example is a square of soil with side 1 meter, where the objective is to know the pore-pressure in the permanent condition and at the same time the vertical displacement were generated, it means that the analysis is coupled and were solved by MPM. In order to make a more realistic application, Palo Redondo dam is analyzed (uncoupled condition), which belongs to the Chavimochic project located in La Libertad, region of Perú. This dynamic analysis was done considering two constitutive models: Elastic and Mohr Coulomb, additionally seismic forces.
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Čechová, Simona. "Vyhodnocení zatěžovacích zkoušek pilot z tryskové injektáže." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2021. http://www.nusl.cz/ntk/nusl-433418.
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The master thesis consists of a theoretical part and a practical part. In the theoretical part jet-grouting technology is described briefly. Mechanical properties of jet-grouted piles were characterized. Various estimation methods of ultimate pile bearing capacity are described in this thesis – analytical calculation of ultimate bearing capacity for bored piles and estimation of ultimate pile bearing capacity by analysis of load-displacement curve defined by CHIN (1970; 1972). Load transfer method for piles and hyperbolic load-transfer curve are introduced. As a part of the load-trasfer method analysis, a method of estimating ultimate pile shaft friction called beta method is defined. In the practical part were evaluated several static load tests of jet-grouted piles and were constructed their load-displacemnt curves. Then reverse analysis of the results from static load tests was performed using load-transfer method. Then ultimate pile bearing capacity was estimated using analytical calculation of pile bearing capacity for bored piles and using analysis of load-displacement curve with method by CHIN (1970; 1972). By evaluation of load transfer method and beta method ultimate shaft resistence for each pile was estimated. Results and load-displacement curves were compared.
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Kiflu, Henok Gidey. "Optimized Correlation of Geophysical And Geotechnical Methods In Sinkhole Investigations: Emphasizing On Spatial Variations In West-Central Florida." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4709.
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Abstract
Sinkholes and sinkhole-related features in West-Central Florida (WCF) are commonly identified using geotechnical investigations such as standard penetration test (SPT) borings and geophysical methods such as ground penetrating radar (GPR) and electrical resistivity tomography (ERT). Geophysical investigation results can be used to locate drilling and field testing sites while geotechnical investigation can be used to ground truth geophysical results. Both methods can yield complementary information. Geotechnical investigations give important information about the type of soil, groundwater level and presence of low-density soils or voids at the test location, while geophysical investigations like GPR surveys have better spatial coverage and can resolve shallow stratigraphic indicators of subsidence.
In GPR profiles collected at 103 residential sites in covered-karst terrain in WCF, sinkhole-related anomalies are identified using GPR and SPT methods. We analyze the degree to which the shallow features imaged in GPR correlate spatially with the N-values (blow counts) derived from SPTs at the 103 residential sites. GPR anomalies indicating sinkhole activity are defined as zones where subsurface layers show local downwarping, discontinuities, or sudden increases in amplitude or penetration of the GPR signal. "Low SPT values" indicating sinkhole activity are defined using an optimization code that searched for threshold SPT value showing optimum correlation between GPR and SPT for different optimal depth ranges. We also compared these criteria with other commonly used geotechnical criteria such as weight of rod and weight of hammer conditions.
Geotechnical results were also used to filter the data based on site characteristics such as presence of shallow clay layers to study the effectiveness of GPR at different zones. Subsets of the dataset are further analyzed based on geotechnical results such as clay thickness, bedrock depth, groundwater conditions and other geological factors such as geomorphology, lithology, engineering soil type, soil thickness and prevalent sinkhole type. Results are used to examine (1) which SPT indicators show the strongest correlations with GPR anomalies, (2) the degree to which GPR surveys improve the placement of SPT borings, and (3) what these results indicate about the structure of sinkholes at these sites.
For the entire data set, we find a statistically significant correlation between GPR anomalies and low SPT N-values with a confidence level of 90%. Logistic regression analysis shows that the strongest correlations are between GPR anomalies and SPT values measured in the depth range of 0-4.5 m. The probability of observing a GPR anomaly on a site will decrease by up to 84% as the minimum SPT value increases from 0 to 20 in the general study area. Boreholes drilled on GPR anomalies are statistically significantly more likely to show zones of anomalously low SPT values than boreholes drilled off GPR anomalies. We also find that the optimum SPT criteria result in better correlation with GPR than other simple commonly used geotechnical criteria such as weight of rod and weight of hammer. Better correlations were found when sites with poor GPR penetrations are filtered out from the dataset. The odds ratio showed similar result while the result varied with the depth range, statistics and threshold SPT value (low N- value with optimum correlation), with a maximum observed odds ratio of 3.
Several statistical results suggest that raveling zones that connect voids to the surface may be inclined, so that shallow GPR anomalies are laterally offset from deeper zones of low N-values. Compared to the general study area, we found locally stronger correlation in some sub-regions. For example, the odds ratio found for tertiary hawthorn subgroup were 25 times higher than the odds ratio found for the general study area (WCF).
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Olhans, Linnéa. "Leksandsbrons deformationsövervakning med geodetiska metoder." Thesis, Högskolan i Gävle, Samhällsbyggnad, GIS, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-26940.
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Av olika orsaker sker rörelser i strukturer, vilket leder till att deformationer uppstår. För att upptäcka deformationer krävs att förändringarna övervakas regelbundet. Övervakning kan ske på olika sätt. När detta utförs bör ett stomnät, upprättat av referenspunkter av god kvalitet, finnas tillgängligt. Stomnätet ger en grund för deformationsmätningen och gör att instrumentet som används, kan erhålla en lokalisering av var referenspunkterna placeras innan mätningen av strukturen utförs. 2014 utförde konsultföretaget Sweco, med uppdrag från Leksands kommun, en deformationsmätning av Leksandsbron, som är en gammal bågvalvsbro från 1925 i Leksands kommun, Dalarnas län. Syftet var att undersöka brons hållbarhet, men några slutsatser kunde inte dras utifrån den mätningen. I denna studie är syftet att ge förslag på hur Swecos stomnät skulle kunna utvecklas. Kompletteringen av stomnätet utfördes genom en simulering i programvaran SBG Geo där ett antal av Swecos kända stompunkter valdes och nya stompunkter placerades ut grafiskt med avseende på kvalitet, tillförlitlighet, geometri och ekonomiska aspekter i tre scenarier. Ett stomnät kan se ut på många olika sätt i teorin, men i praktiken är omgivningen begränsad vid bromätningar. Nätutjämning av förslagen fick senare klargöra vilket nät som var det bästa för att använda som referens till inmätningen av bron. Kompletteringen resulterade i att det förslag som var det mest lämpade också var det som var bäst anpassat till brons omgivning, natur och sikt. Det bästa förslaget har därefter användes därefter till inmätning av Leksandsbron, där Swecos deformationsmätning utgjorde referens. Inmätningen av stomnätet och bron utfördes med totalstationen Trimble S7. Genom nätutjämning beräknades nätets koordinater och osäkerheter från observationerna och differenserna jämfördes mot Swecos punkter för att se om någon deformation uppstått. Resultatet visar att två av Swecos punkter och några av brons punkter har utsatts för deformation. Deformationen för punkternas avvikelser analyserades också genom att använda t-student signifikanstest på ett konfidensintervall av 95%. Är avvikelsen inom intervallet har punkten inte rört sig och är avvikelsen utanför konfidensintervallet har punkten rört sig. Signifikanstestet visade att de punkter som utsatts för deformation i nätutjämningen även är signifikanta i t-student testet och bekräftade att punkterna har rört sig.For different reasons there are movements in structures, which leads to deformations. To monitor deformations, the changes have to be monitored on a regular basis. Monitoring can take place in different ways. When doing this, a core network based on good quality reference points, should be available. The core network provides a basis for deformation measurements and allows the instrument to predict a suitable location before measuring of the structure. In 2014, the consultancy company Sweco, commissioned by Leksands municipality, made deformation measurements of Leksandsbron, an old arch bridge from 1925, situated in Leksand, Dalecarlia. The intention was to investigate the sustainability of the bridge, but it was not possible to draw any conclusions from the measurements from 2014. The purpose of this study is to give suggestions on how the core network from Sweco could be developed. The completion was performed by a simulation in SBG Geo Software where some known points from Sweco were chosen as a reference and new points were graphically placed in terms of quality, reliability, geometry and economic aspects in three scenarios. A core network can look in many different ways theoretically, but practically, and especially at bridge measurements, there are limitations. By network adjustment of the proposals it could be clarified, which network was the best one to use for the survey of the bridge. The result of the completion was that the best suited proposal also was the one best suited to the surroundings, nature and visibility of the bridge The best suggestion was used for the bridge measurement with Sweco´s deformation measurement as a reference. The survey of the core network and the points of the bridge was performed by the Trimble S7 total station. With network adjustment the coordinates and assurances were calculated and the differences were compared to Sweco points to see if any deformation had occurred. The result showed that two of Sweco´s points and some of the bridge points have been exposed to deformation. The deformation has also been analyzed for the deviations of the core network points and the bridge points by using t-student significance test of a confidence interval of 95%. If the deviation is within the range it´s considered that the point has not moved and if the deviation is outside the range it´s considered that the point has moved. The significance test showed that the same points that had been exposed to deformation in the network adjustment, also were significant in the t-student test, which confirms that the points have moved.
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Arens, Kevin C. "Remediation Methods for Subgrade Settlements of Existing Roadways: Lifetime Cost-Benefit Analysis." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1575537943683836.
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Brinck, Mårten, and Karl Stigenius. "Jet grouting as a method for sealing sheet pile excavations in Swedish conditions : A probabilistic approach." Thesis, KTH, Jord- och bergmekanik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259693.
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Jet grouting is a groundimprovement method that creates cemented columns in the soil. The soil isinjected with different pressurized fluids, through the monitor, to replace andcement the soil, often with water cement grout. There are three different commonsystems for ejecting the fluids, the single, double and triple fluid system.The process is performed from the ground surface by drilling to desired depthand then withdrawing the monitor while rotating and ejecting and thus creatinga column. There are many applications for this technique. However, this thesisfocus on using jet grouted columns in formation to seal sheet pile excavationsfrom water.
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Bergman, Stina. "Livscykelanalys för grundläggning av byggnader : Användningen idag och hur metoden kan tillämpas i praktiken." Thesis, Luleå tekniska universitet, Arkitektur och vatten, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71087.
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Byggsektorn står idag för en stor andel av växthusgasutsläppen vid produktion av byggmaterial ochanvändningen av byggmaskiner under byggproduktionsskedet. Det nationella målet är att Sverige år 2045ska vara koldioxidneutralt och utifrån detta mål har Fossilfritt Sverige, tillsammans med ett stort antalaktörer från bygg- och anläggningssektorn, tagit fram en färdplan för hur branschen ska bli klimatneutralt.Grundläggning står för en betydande del av den totala byggnadens klimatpåverkan och för att nå måletmed ett klimatneutralt Sverige år 2045 är det viktigt att discipliner inom grundläggning börja arbeta medutveckling och optimering av grundläggningskonstruktioner för att minska klimatpåverkan. I detta examensarbete har en intervjustudie utförts för att kartlägga vilka aspekter som styr valet avgrundläggningsmetod idag utifrån entreprenören och konsultens perspektiv samt för att kartlägga hurdessa aktörer använder livscykelanalys inom grundläggning av byggnader. En fallstudie har utförts för attundersöka hur livscykelanalys kan användas för att beräkna och jämföra klimatpåverkan samtprimärenergianvändningen från grundläggningsmetoder för byggnader genom att prova och utvärderatvå digitala LCA-verktyg. En litteraturstudie har genomförts för att skapa kunskap inom grundläggning och för att skapa förståelseom klimatpåverkan från byggsektorn samt vilka klimatkrav som finns. Litteraturstudien har legat till grundför valet av de två digitala LCA-verktyg som används i fallstudien samt har används för att ta fram enintervjuguide. Intervjuer har genomförts med aktörer från konsult- och entreprenadföretag som harvarierande erfarenheter och kunskaper inom livscykelanalys för grundläggning. Vidare har en fallstudiegenomförts där en jämförande livscykelanalys utförs mellan två grundläggningsmetoder, platta med pålaroch platta med lastkompensation, genom att använda två digitala LCA-verktyg, Klimatkalkyl 6.0 och BM1.0. LCA-studien utgår från verktygens avgränsningar och beaktar endast första delen av livscykeln,byggskedet (modul A1-A5) där Klimatkalkyl 6.0 beräknar klimatpåverkan och primärenergianvändningenoch BM 1.0 beräknar endast klimatpåverkan. Resultatet från intervjuerna visar att grundläggningsmetoder ofta väljs utifrån den ekonomiska aspektenmen att personlig erfarenhet, geografisk och historisk tradition även påverkar. Respondenterna anser attklimat- och miljökrav som förekommer i projekt ofta är otydliga och svåra att förstå. Intervjustudienindikerar att användningen av livscykelanalys är begränsad. Enligt respondenterna skulle användningenöka om man utvecklade kompetens hos konsulter och entreprenörer, förenklade LCA-modellen menframförallt om deras beställare tydliggjorde kravställningarna. I fallstudien visar de två verktygen på olika klimatpåverkan för respektive grundläggningsmetod och olikaskillnader vid jämförandet av de två grundläggningsmetoderna. Båda verktygen visar att grundläggningmed platta med pålar ger en lägre klimatpåverkan än platta med lastkompensation under byggskedetmed givna förutsättningar. Skillnaden mellan grundläggningsmetoderna är 2 eller 5 tonkoldioxidekvivalenter beroende på vilket verktyg man använder, vilket motsvarar cirka 13 respektive 23procent i skillnad. Båda verktygen visar även att betong, cellplast och stål är de byggnadskomponentersom bär den största andelen av den totala klimatpåverkan för respektive grundläggningsmetod. Ingen av verktygen Klimatkalkyl 6.0 och BM 1.0 är utvecklade för grundläggning av byggnader och i bådaverktygen saknas det byggnadsdelar som ingår i grundläggningsmetoderna, som studeras i fallstudien.Resultatredovisningen från respektive verktyg är även svårtolkade och bör utvecklas. Trots detta så ansesdet att båda verktygen kan användas som hjälpmedel för att beräkna och visa vilketgrundläggningsalternativ som ger minst klimatpåverkan. Då den ekonomiska faktorn idag är styrande för valet av grundläggningsmetod kan denna parameteranvändas som styrmedel för att öka arbetet med klimatanpassade lösningar. Förslag på fortsatta studierär att ta fram en relation mellan kostnader och klimatpåverkan för grundläggningsmetoder samt attundersöka hur man kan implementera livscykelanalys på projektörsnivå för att öka dess användning.Today, the building sector accounts for a large part of greenhouse gas emissions during the production ofbuilding materials and the use of construction machinery during the construction phase. The national goalis that Sweden, as a country, will be carbon neutral country in 2045. Based on this goal, Fossilfri Sverige,together with a large number of companies from the building and civil engineering sector, has developeda plan of action for the industry's climate neutrality. Foundations account for a significant part of the totalcarbon footprint of building and in order to reach the goal of a climate neutral Sweden in 2045, it isimportant that disciplines working with ground foundations, begin to develop and optimize foundationconstructions to reduce the carbon footprint. In this master thesis, an interview study has been conducted to map which aspects affect the choice offoundation methods today, based on the contractor and the consultant's perspective, and map how theseactors use life cycle assessment (LCA) in foundations of buildings. A case study has been conducted toinvestigate how life cycle assessment can be used to calculate and compare carbon footprint and primaryenergy use from two foundation methods, by using and evaluating two digital LCA tools. A literature study has been conducted to find knowledge about foundation of buildings and to create anunderstanding of the climate impact from the building sector and the climate requirements in the buildingindustry. The choice of the two digital LCA tools used in the case study and the creation of the interviewguide is based on the literature study. The interviews have been conducted with employers fromconsultant and contractors who have varied experience and knowledge about life cycle assessment offoundations. In addition, a case study has been conducted in which a comparative life cycle assessment isexecuted for two foundation methods, pile foundation and compensated foundation, by using two digitalLCA tools, Klimatkalkyl 6.0 and BM 1.0. The LCA study is based on the limitations of the tools, consideringonly the first part of the life cycle; the construction phase (module A1-A5). Klimatkalkyl 6.0 calculatescarbon footprint and the primary energy use, and BM 1.0 calculates carbon footprint. The results of the interviews indicate that founding methods are often selected based on economicaspects, but also on personal experience, geographical location and tradition. The respondents mentionthat when climate and environmental requirements occur in projects, they are often unclear and difficultto understand. The interview study indicates that the use of LCA is limited. According to the respondents,the use of LCA would increase by improved knowledge about the method, by simplifying the LCA modelbut above all if their clients clarified the climate requirements. In the case study, the two tools show different climate impacts for the respective foundation method anddiverse differences in the comparison of the two foundations. Both tools show that foundation with pilefoundation gives a lower climatic impact than compensated foundation, during the construction phase.The difference between the foundation methods is 2 or 5 tonnes of carbon dioxide equivalents dependingon the tools, which corresponds to approximately 13 and 23 percent, respectively. Both tools also showthat concrete, styrofoam and steel are the building components that carry the largest part of the totalclimate impact for each foundation method. None of the tools, Klimatkalkyl 6.0 or BM 1.0, are developed specifically for the foundation of buildings,and in both tools there are building components missing that are included in the foundation methodswhich are studied in the case study. The result report from the respective tools is also difficult to interpretand should be developed. In spite of this, the conclusion is that both tools can be used as an aid tocalculate and show which foundation option will generates the lowest carbon footprint. As the economic factors today affects the choice of foundation method, this parameter can be used as ameans of increasing work on climate-adapted solutions. Proposals for further studies are to establish arelationship between costs and climate impacts for foundations and to investigate how to implement andincrease the use of life cycle assessment on a design level.
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Bloodworth, Alan Graham. "Three-dimensional analysis of tunnelling effects on structures to develop design methods." Thesis, University of Oxford, 2002. http://ora.ox.ac.uk/objects/uuid:9c789d79-efa1-43fa-b2e1-e08d01de63db.
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The subject of this thesis is the verification of a three-dimensional numerical modelling approach for the prediction of settlement damage to masonry buildings due to tunnelling in soft ground. The modelling approach was developed by previous researchers at Oxford, and was applied to three sites, representative of a range of practical configurations. The first involved the excavation of a shaft close to the corner of an eighteenth century church in London. The second involved tunnelling with very low cover beneath the foundations of a terrace of cottages at Ramsgate, Kent. The third was the relatively well-known case of tunnelling beneath the Mansion House, London, for construction of the extension to the Docklands Light Railway in the late 1980’s. The overall conclusion of the project is that the modelling procedures are suitable for application to the detailed assessment of the response of buildings to tunnelling. Particular features of the procedures are that the building is modelled together with the ground and a representation of the tunnel excavation, and in three dimensions. It has been confirmed that all these features are necessary to model the building response, which may include a combination of shear deformation, arching and bending behaviour. Further lessons have been learned concerning the importance of the self-weight of the building in determining overall settlements, how to model openings such as doors and windows in façades, and whether it is necessary to model the building foundation. It has not proved possible, through lack of time, to model the advance of tunnels beneath buildings within this thesis. This, however, is observed to be an important effect in the field, particularly in causing damage to internal walls. It is recommended that further research be carried out in this area. This project made use of large-scale non-linear finite element analysis. The demand on computing resources was high, stimulating many enhancements to the software, the most important of which was parallelisation of the analysis program for use on the Oxford Supercomputer. To obtain optimum results, larger model sizes are required. The computing resources to enable this should become more commonly available within the next few years, enabling the modelling techniques to be used routinely.
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Silva, João Paulo de Sousa. "Avaliação da influência do regime de fluxo no comportamento geotécnico de uma barragem de rejeito alteada pelo método de montante." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3145/tde-28082015-145835/.
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A presente pesquisa faz uma avaliação da influenciado regime de fluxo na estabilidade de uma barragem construída pela disposição hidráulica de rejeitos. Usualmente, essas estruturas são avaliadas com modelos de equilíbrio limite adotando-se, de modo simplificado, uma superfície freática em um regime hidrostático. No entanto, em casos em que a condutividade hidráulica da fundação ou de camadas na base do aterro é relevante em relação à dos rejeitos, o fluxo se torna verticalizado e o gradiente significativo, portanto, a premissa de regime hidrostático se torna não válida. Com o objetivo de avaliar a influência desses fatores, foram realizadas análises numéricas, simulando condições de fluxo e seus reflexos nos fatores de segurança. Ademais, foi desenvolvida uma extensa análise de dados e cálculos no estudo de caso de uma barragem, com expectativa de ampliar a vida útil de uma Planta de beneficiamento de minério de ferro. Ao se incorporar a real distribuição de pressões neutras, medidas na barragem, concluiu-se que o seu Fator de Segurança era cerca de 20% maior do que o obtido em cálculos simplificados, que desconsideram o regime de fluxo descendente, admitido, por hipótese, na barragem em estudo. Alguns comentários quanto à segurança à liquefação foram feitos, exceto a liquefação dinâmica, que foge do escopo desse trabalho.The present research evaluates the influence of the foundations permeability in the scheme of flow and in the stability of a dam built through the hydraulic tailings disposal. Usually, these structures are evaluated with models of equilibrium limit, considering, in a simplified way, a phreatic surface in a hydrostatic scheme. However, in cases in which the foundations hydraulic conductivity is relevant when related to the tailings, the flow becomes verticalized and the gradient becomes significant. Therefore, the hydrostatic scheme premise becomes not valid. With the purpose of evaluating the influence of these factors, numerical analysis were made, simulating flow conditions and their influence in the factor of safety. Moreover, an extensive data and calculations analysis was developed in the case study of a dam, with the expectation of increasing the lifetime of an ore mining beneficiation plan. When incorporating the actual distribution of porepressure, measured at the dam, it was concluded that the safety factor of the dam was about 20% higher than that obtained for simplified calculations, that disregard the downward flow regime, admitted in the dam under study. Some comments about the safety of liquefaction were made, except the dynamic liquefaction, beyond the scope of this work.
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Ravjee, Sachin. "Discrete element modelling investigating the effect of particle shape on backfill response behind integral bridge abutments." Diss., University of Pretoria, 2018. http://hdl.handle.net/2263/64125.
Full textAbstract:
Integral bridges are designed without expansion joints or bearings to eliminate the maintenance and repair costs associated with them. Thus, the expansion and contraction due to daily and seasonal temperature variations of the deck of the bridge are restricted by the abutments, causing the abutments to move cyclically towards and away from the granular material used as backfill. This movement results in a stress accumulation in the backfill retained by the abutments. The Discrete Element Method (DEM) was used was used to perform a numerical sensitivity analysis, investigating the effect of granular particle shape on the response of backfill material retained by integral bridge abutments.
Two DEM software suites were used to perform the simulations, namely STAR-CCM+, a commercial code, and Blaze-DEM, a research code under development at the University of Pretoria. Blaze-DEM makes use of Graphics Processing Unit (GPU) computing as opposed to traditional Central Processing Unit (CPU) computing. Blaze-DEM delivered computational times over 150 times faster than the equivalent simulation in STAR-CCM+. The results from the numerical sensitivity analysis showed that the particles with lower sphericities (higher angularities) experienced larger accumulations of stresses on the abutment as opposed to the more spherical particles. This was suggested to be a result of particle interlocking and reorientation.Dissertation (MEng)--University of Pretoria, 2018.
Civil Engineering
MEng
Unrestricted
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Martos, Justin Riley. "Fault Mapping with the Refraction Microtremor and Seismic Refraction Methods along the Los Osos Fault Zone." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/873.
Full textAbstract:
The presence of active fault traces in proximity to any new infrastructure project is a major concern for the design process. The relative displacements that can be experienced in surface fault rupture during a seismic event must be either entirely avoided or mitigated in some way. Blind faults present a significant challenge to engineers attempting to identify these hazards. Current standards of practice employed to locate these features are time consuming and costly. This work investigates the geophysical methods of refraction microtremor (ReMi) and seismic refraction with regard to their applicability in this task. By imaging a distinct lateral variation in the shear wave velocity (Vs) profile across a short horizontal distance, these methods may provide a means of constraining traditional investigation techniques to a more focused area. The ReMi method is still very new, but holds key advantages over other geophysical methods in its ease of application and ability to achieve good results in highly urban settings. It is one of the few geophysical techniques that does not suffer in the presence of high amplitude ambient vibrations. The seismic refraction method is here applied in an attempt to corroborate data obtained through the ReMi analysis procedure. Sensitivity, precision parametric studies are carried out in order to learn how to best apply the ReMi method. Both tests are then applied at a previously trenched fault trace to determine whether the data can be matched to the subsurface information. Finally, the methods are deployed at a location with an inferred fault trace where little to nothing is known about the subsurface. The precision study indicates a coefficient of variation for the ReMi method on the order of 7%. At the known fault trace both methods generally agree qualitatively with available subsurface data and each other. Using the ReMi method, a marked shift is observed in the Vs profile laterally across the fault trace. In the case of the inferred fault trace, the same type of lateral variation in the Vs profile is observed using the ReMi method. The seismic refraction at this site does not agree with the ReMi data, but seems reasonable given the visible geomorphology. Receiver arrays placed in close proximity to the inferred fault trace recorded erratic signals during seismic refraction testing, and displayed abnormal response modes after transforming the ReMi data to frequency-slowness space. These anomalies may possibly be attributed to the presence of abnormal subsurface structural geometry indicative of faulting.
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Ratel, Alain. "Modélisation d'un sol renforcé par géosynthétique : application de la "méthode en déplacements"." Grenoble 1, 1987. http://www.theses.fr/1987GRE10110.
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Pour les sols renforces, en particuler pour ouvrages de soutenements, etude du phenomene de l'interaction et proposition d'une nouvelle methode d'equilibre limite dite des "deplacements", prenant en compte la deformabilite du geotextile; nombreux exemples de calculs
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Emanuelsson, Patrik. "Study of a new method to measure the stresses in rock by image technology : Use of sawn slots and DIgital Image Correlation." Thesis, Luleå tekniska universitet, Geoteknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68646.
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In rock constructions and mining it is important to know the current stress situation in the rock due to safety and construction reasons. Two of the widely used stress measurement methods are overcoring and hydraulic fracturing. Both methods are expensive, need new boreholes, and are complex and time consuming. The methods are also limited by the number of successfully achieved measurements series. An alternative method is therefore investigated by locally relieving stresses around the borehole wall using sawn slots. To determine the stresses in the rock, strain measurements will be done using optics and image processing of images taken before and after cutting of the slots. The images will be processed by a technique called Digital Image Correlation (DIC), a method where the pixels are fitted between the images by the greyscale. The thesis is roughly divided into three parts. The first part explains the basics of rock stresses and current stress measurement methods. The second part is a literature study of the theory behind optics and DIC. There is also a study about if it is possible to use optics from a smartphone and how it differs from a reference commonly used camera in DIC application. Last part consists of numerical calculations in 2D to investigate if there is a possibility to relieve the stress around the borehole walls by cutting slots. With the optics from a smartphone the borehole wall can be in focus on just a few millimeters distance. DIC is a well-developed method which has a good precision when being conducted right and with a good image quality. The combination of using a smartphone and DIC is, however, not fully investigated yet. Only one comparable study was found. It used a Sony tablet and measured the deformations instead of strains. However, that study showed that the measurement error was around 1% compared to the reference camera. When translating deformations into strains, it is most likely that the error will increase, because the error will also be affected from the difference in deformation before and after cutting the slots. The numerical part showed that it’s possible to relieve the stress at parts of the borehole walls for the investigated conditions. To fully relieve the stresses around the borehole wall, it is necessary to have two slots with a short c-c distance and relatively deep slots. In this case a c-c distance of 15 mm and slot depth of at least 25 mm are recommended.Vid projekt inom berganläggningar och gruvor är det viktigt att känna till de rådande spänningar i berget i ett säkerhets- och konstruktionsperspektiv. I Sverige används framförallt två undersökningsmetoder - överborrning eller hydraulisk spräckning. Två metoder som dock är dyra och relativt få mätserier kan genomföras. En alternativ metod har därför undersökts där borrhålsväggen lokalt avlastas genom sågade slitsar. Töjningsmätning sker genom att fotografera borrhålsväggen innan och efter sågning av slitsarna. Därefter sker bildbehandling via Digital Image Correlation (DIC). En metod som jämför en pixels placerings förändring genom att matcha pixeln via gråskalan. Examensarbetet kan man säga är grovt indelat i tre delar. Den första delen innefattar teorin som handlar om bergspänningar samt nuvarande mätmetoder för att mäta bergsspänningar. Andra delen är en litteraturstudie som behandlar den bakomliggande teorin för optik och bildbehandling med DIC samt en kort undersökning om det är möjligt att använda den optiska tekniken som finns i en smartphone. Sista delen utgörs av numeriska modelleringar i 2D för att verifiera om det går att fullständigt avlasta ett borrhål genom sågade slitsar. Med optik som finns i en smartphone kan bergväggen vara i fokus på bara ett par millimeters avstånd. DIC i sig är en teknik som är så pass utvecklad att precisionen i mätningarna är väldigt god. Förutsatt att bildbehandling görs korrekt och bildkvalitén är god. Kombinationen med optik liknande den från smartphone och bildbehandling med DIC är dock inte fullständigt undersökt. Enbart en jämförbar studie har hittats där deformationsmätningar har gjort med hjälp av en Surfplatta från Sony. Denna undersökning visade att mätfelet mot en referenskamera är cirka 1%. Dock förstärks mätfelet vid töjningsmätningar. Förstärkningen beror dock även av deformationsskillnaden mellan innan och efter avlastning. Den numeriska delen har visat att det går att lokalt avlasta bergväggen fullständigt för det undersökta spänningsförhållandet. Dock krävs det att två slitsar sitter på ett litet c-c avstånd samt är relativt djupa. Två undersökta slitsuppsättningar har visat på fullständigt avlastning, samt ytterligare ett fall som skulle kunna vara användbart.
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Modenese, Chiara. "Numerical study of the mechanical properties of lunar soil by the discrete element method." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:c8908ef8-9652-4e8d-9b2f-49770f3ce815.
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Lunar soil, defined as the finest part of the lunar regolith which covers the entire surface of the Moon, has shown to have remarkable shear strength properties, highlighted by the clearly visible effects of soil cohesion. The main objective of this thesis is to unveil the physical explanations causing this unusual soil behaviour in a waterless, airless, lunar environment. Ultra-High Vacuum (UHV), in particular, is considered responsible for increasing the strength of surface energy forces due to lunar soil outgassing. In turn, the presence of surface energy forces, arising from van der Waals intermolecular forces, is thought to alter the mechanical properties of lunar soil. A particle-based microscopic approach by means of the Discrete Element Method (DEM) was utilised to investigate the effects of surface energy forces on the macroscopic soil be- haviour. A micro-mechanical contact model, based on the JKR theory, was selected to describe the inter-granular behaviour between lunar soil particles. Physical and geometrical parameters typical of lunar soil were employed. Several triaxial tests were run to identify a link, if any, between the microscopic surface energy parameter and the macroscopic soil cohesion, which was interpreted as a true soil cohesion. In addition, very low stress levels and high soil densities were simulated in order to take into account the low gravitational field and the high state of soil compaction caused by continuous meteorite impacts on the Moon. Results from triaxial tests were analysed at both the peak and critical state. It was found that in the ideal case of perfectly spherical grains, the presence of adhesion is a source of noticeable macroscopic soil cohesion. However, no influence was observed in terms of macroscopic friction angle. Furthermore, a brittle macroscopic soil behaviour was revealed, owing to the simulated inter-granular chemical bonds and the very low stress conditions applied. Finally, similar to the behaviour of cemented sands, very little cohesion was recorded at the critical state. Subsequently, particle shape effects were investigated by complementing the numerical model with a simple form of inter-particle rolling resistance. Simulations were also run with non-convex grains of increasing geometrical complexity in order to simulate more realistically the irregular shapes of lunar soil grains. In both cases, the interplay of surface energy forces with particle shape effects resulted in even higher shear strength, with predictions similar to the estimates of shear strength for real lunar soil. Once again, the peak strength was dominated by macroscopic cohesion which, on the other hand, was hardly observable at the critical state, confirming the tendency observed from spherical grains. Finally, the practical implications of the above findings were discussed in terms of bearing capacity, trafficability and slope stability on the lunar surface. In particular an analytical approach, based on the bearing capacity problem, was devised to study the performance of a rigid wheel rotating on a lunar terrain and operating under different dynamic conditions.
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Agreda, Principe Santos Oliver, and Ascencio Erick Andrés Avila. "Análisis probabilístico de riesgo geotécnico en excavaciones profundas utilizando anclajes post-tensados en edificaciones de Lima Metropolitana." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/652547.
Full textAbstract:
La presente investigación tuvo como objetivo principal, determinar el riesgo geotécnico de excavaciones profundas utilizando anclajes post-tensados en edificaciones de Lima Metropolitana, aplicando métodos probabilísticos a partir de un abordaje estadístico simple, basado en la hipótesis fundamental de la distribución normal gaussiana de las variables envueltas.En primer lugar, se utilizó el parámetro fundamental de los anclajes post-tensados, la capacidad última de adherencia en la interacción suelo-lechada de cemento τult, (resistencia en la ruptura). Este parámetro se obtuvo de dieciséis (16) ensayos de arrancamiento a escala natural de anclajes post-tensados cimentados en el conglomerado de Lima Metropolitana, obtenidos de la tesis de maestría de Puelles (2011).
En segundo lugar, se realizó un diseño de anclajes post-tensados de edificaciones en Lima Metropolitana de 3, 4 y 5 anillos de 10.50, 13.50 y 16.50 m de profundidad respectivamente. Para ello, se utilizó la metodología FHWA con el objetivo de obtener la capacidad de carga de diseño (TD) de anclajes post-tensados. Además, se ejecutó modelos y modelamientos en el software Slide v6.0 (método equilibrio límite), para realizar el análisis de estabilidad de los mismos. Para ello, se tuvo en cuenta las siguientes variables: los parámetros geotécnicos representativos de Lima Metropolitana, la profundidad de estudio (10.50 a 16.50 m.) y la sobrecarga de edificaciones colindantes. Por último, con los parámetros obtenidos (τult y TD) se definió las curvas estadísticas de distribución de solicitación y resistencia. Luego, se aplicó los métodos probabilísticos e interpretación respectiva, determinado así el riesgo geotécnico para cada caso de estudio.The main objective of this research was to determine the geotechnical risk of deep excavations using post-tensioned anchors in buildings in Metropolitan Lima, applying probabilistic methods based on a simple statistical approach, based on the fundamental hypothesis of the Gaussian normal distribution of the variables wrapped. Firstly, the fundamental parameter of the post-tensioned anchors was used, the ultimate capacity of adhesion in the soil-cement grout interaction τult, (resistance to rupture). This parameter was obtained from sixteen (16) natural scale pull-out tests of post-tensioned anchorages cemented in the conglomerate of Metropolitan Lima, obtained from the master's thesis of Puelles (2011). Secondly, a design of post-tensioned anchorages of buildings in Metropolitan Lima of 3, 4 and 5 rings of 10.50, 13.50 and 16.50 m depth, respectively, was carried out. For this, the FHWA methodology was used with the objective of obtaining the design load capacity (TD) of post-tensioned anchors. In addition, models and modeling were executed in the Slide v6.0 software (limit equilibrium method), to perform their stability analysis. For this, the following variables were taken into account: the representative geotechnical parameters of Metropolitan Lima, the study depth (10.50 to 16.50 m.) And the overload of neighboring buildings. Finally, with the obtained parameters (τult and TD) the statistical curves of the distribution of stress and resistance were defined. Then, the probabilistic methods and respective interpretation were applied, thus determining the geotechnical risk for each case study.
Tesis
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Jedenius, Arthur. "Internal Erosion and Dam Stability : Analysis of the internal erosion effects on stability of an embankment dam." Thesis, Luleå tekniska universitet, Geoteknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68551.
Full textAbstract:
Embankment dams encounter several problems in terms of dam safety. One of those problems is called internal erosion. This phenomenon is induced by the movement of fine particles within the dam due to seepage forces. If the dam is not able to self-heal, the eroded zones will increase which will eventually cause the dam to fail. Thus standards have been created by Svensk Energi and summarized in the Swedish dam safety guideline RIDAS 2012. These standards are used as a basic in the risk analysis of existing dams and provide guidelines for proper design of future dams.A dam in Sweden has presented recurring incidents related to internal erosion within the core. The impact of this internal erosion is analysed in this thesis with the use of Finite Element Method/Analysis (FEM/A). FEA models simulate the in situ stresses in the dam and calculate the strength. It also enables the analysis of changing hydraulic conductivity and its effect on the overall effective strength due to changing pore pressure and seepage forces. The analysis using numerical methods was performed in the program PLAXIS2D and SEEP/W while limit equilibrium analysis was done in SLOPE/W.The calculation in PLAXIS2D was performed by using the Mohr-Coulomb constitutive model. The in situ stresses are initially calculated using gravity loading since this is the preferred method on an uneven terrain instead of a K0-calculation. Then, through a set of phases in the program, zones where erosion is assumed to have occurred are changed. These zones have a higher permeability and will thus affect the pore pressures in the dam following Darcy’s law with permeability through a set medium.The increased permeability is set to follow an increased void ratio due to loss of fine material in the core. How this increase of void ratio affects the permeability is investigated through using Ren et al’s (2016) proposed equation for calculating permeability with a set void ratio. Their equation, apart from the usually used Kozeny-Carman equation, considers both effective and ineffective void ratio where the ineffective void ratios refers to the volume of pores that is immobile when flow is considered.The increased flow in the eroded zones of the core did not seem to impact the strength of the dam in much regard. The phreatic surface and thus the pore pressure did not change enough to influence the overall effective strength of the dam. It raises the question if the stability of an earth-rock fill dam will be affected due to increased pore pressure at all due to its draining properties and if it would rather fail due to increased seepage forces.
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Stoklasová, Andrea. "Silové a deformační chování duktilních mikropilot v soudržných zeminách." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409752.
Full textAbstract:
This thesis is focused on creation of mobilization curves, based on data, obtained from standard and detailed monitoring of the load test. The load test was performed on the 9 meters long ductile micropile. The first part of the thesis explains the methods and principles, which was used to construct the mobilization curves. Next there is description of the technologies of ductile micropiles and the load test. In the next part of the thesis is generally explained process, which was applied to the evaluated data. For evaluation was used spreadsheet Microsoft Excel and programming language Matlab, with Kernel Smoothing extension. In the last chapter of the thesis there are interpreted the load transfer function together with skin friction and micropile displacement.
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Intsiful, Sekyi K. "DEFORMATION-BASED EXCAVATION SUPPORT SYSTEM DESIGN METHOD." UKnowledge, 2015. http://uknowledge.uky.edu/ce_etds/29.
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Development in urban areas around the world has steadily increased in recent years. This rapid development has not been matched by the ever decreasing open space commonly associated with urban centers. Vertical construction, thus, lends itself a very useful solution to this problem. Deep excavation is often required for urban construction. Unfortunately, the ground movements associated with deep excavation can result in damage to adjacent buildings. Thus, it is critically important to accurately predict the damage potential of nearby deep excavations and designing adequate support systems.
A new design method is proposed, as an attempt, to address the problem. The method is semi-empirical and directly links excavation-induced distortions experienced by nearby buildings and the components of the excavation support system. Unlike, the traditional limit equilibrium approach, the method is driven by the distortions in adjacent buildings. It goes further to propose a preliminary cost chart to help designers during the design phase. The benefit is that initial cost is known real time and will help speed up making business decisions. A new design flowchart is proposed to guide the designer through a step-by-step procedure.
The method is validated using 2D Plaxis (the finite element program) simulation. Though the nature of deep excavation is three-dimensional, a plane strain condition is valid when the length of the excavation is long. Hence, two-dimensional finite element simulation was considered appropriate for this effort. Five hypothetical cases were compared and the model performed very well. The lack of available literature on this approach made verification difficult. It is hoped that future case histories will be used to ascertain the veracity of the deformation-based design method.
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Skarvelas, Georgios Aristeidis. "Reinforcement and Bonded Block Modelling." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-85984.
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The objective of this master’s thesis is to evaluate the use of Bonded Block Modelling (BBM) in 3DEC software combined with hybrid rock bolts, for three different cases. These cases included the laboratory rock bolt case, the shearing case and the blocky rock mass case. 3DEC is a Distinct Element Method (DEM) numerical software which can be used to simulate both continuum and discontinuum media in 3D. The Bonded Block Model in 3DEC can be used to simulate a rock mass as bonded polyhedral elements. The BBM is a relatively new numerical modelling technique. Earlier studies have focused mainly on laboratory test cases and less on field scale studies. The laboratory rock bolt test was introduced by Hoek and the main idea was to describe the way that rock bolts work. Four different rock bolt spacing designs were simulated and one unsupported model, in order to validate Hoek’s results. The diameter of the blocks was 15 cm while the zones were modelled with length of 5 cm. The tunnel on the shearing case was excavated at the depth of 1500 m. For the stress field, the in-situ stresses of Kiirunavaara mine were considered. The tunnel on the blocky case was excavated at the depth of 30 m and a gravitational stress field was assumed. The shearing model as well as the blocky model, were simulated on a quasi-3D model. The zone length for both cases was 0.1 m. In both cases, a discontinuum non-BBM was modelled first and then, a discontinuum BBM with different rock UCS values was simulated. The discontinuum BBM on the shearing case was simulated for rock UCS of 200, 100, and 50 MPa, while on the blocky case, it was simulated for rock UCS of 50 MPa. The Mohr – Coulomb constitutive model was selected for all three modelling cases. The conclusions of this work were the following: – The laboratory rock bolt model validated the results of Hoek. Hoek suggested that rock bolt spacing less than three times the average rock piece diameter would be sufficient to produce positive results. The stabilization of the rock pieces as well as the forming of the compression zone were achieved when this equation was satisfied. The geometry of the stabilized material as well as the compression zone, were also correct. – The discontinuum BBM on the shearing case with intact rock UCS of 200 MPa, produced similar results as the discontinuum non-BBM. This indicates that BBM can be applied for these cases and produce reliable results. The displacement of the fault was expected to be higher than the resulting values. The discontinuum BBM with reduced rock strength (100 MPa and 50 MPa) resulted in rock mass fragmentation. However, the fragmented rock pieces did not detach from the rock mass as the displacement values were not high enough. – The discontinuum BBM on the blocky case with intact rock UCS of 50 MPa, produced similar results as the discontinuum non-BBM. There were two discontinuities that affected the smooth transition of the displacement/stress results on the different blocks. The fragmentation of the rock mass due to the existence of the discontinuities did not produce any further rock mass movements. – The interaction between rock mass and rock bolts was evident in any modelling case. For the laboratory rock bolt model, the hybrid bolts design was vital for producing correct results. For the shearing model, the hybrid bolts were subjected to shearing movements due to fault movements. In the blocky model, the bolts in the roof of the tunnel were subjected to axial displacements, due to the existence of blocks. The recommendations for further work were the following: – The hybrid bolts in the laboratory rock bolt test were pretensioned only in the beginning of the computation phase. In reality, the tensioned bolts act at every moment and not only in the beginning. However, it would be interesting to see if the results are similar with continuously tensioned hybrid bolts. It is anticipated that the constantly tensioned hybrid bolts should be able to keep the compressive zones with high values throughout the whole cycling process. Thus, it is suggested for future modellers that this case could be modelled with continuously tensioned hybrid bolts. – The installation of rock bolts in the shear case as well as in the blocky case, was at the exact same time as the tunnel was excavated. This is not realistic fact because it is impossible to install the rock bolts exactly the same time as the tunnel excavated. Thus, it is suggested that those two cases could be modelled in the future with more focus on the stress relaxation factor.
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Korkjian, Rafy. "Studie av effektiviseringsmöjligheter avseende dimensionering av typförstärkningslösningar i infrastrukturprojekt." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-80135.
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Berganläggningar kräver oftast någon form av bergförstärkning. Vid projektering av nya berganläggningar används typförstärkningslösningar, vilket innebär en typ av bergförstärkning som är repeterbar för vissa i förväg bestämda kriterier. De styrande parametrarna är vanligtvis spännvidd och bergkvalité. Tidigare byggda tunnlar har medfört flera dimensionerade typförstärkningslösningar för olika förutsättningar och förhållanden. Det är därför fördelaktigt att studera tidigare projektering och dimesionering av typförstärkningslösningar. Syftet med examensarbetet var att undersöka effektiviseringsmöjligheterna avseende dimensionering av typförstärkningslösningar. En fallstudie genomfördes, där sju olika projekt studerades, dessa var Citybanan, Nya tunnelbanan, Norrbotniabanan, Hallsberg - Stenkumla, Hamnbanan, Botniabanan och Förbifart Stockholm. För respektive projekt analyserades geologiska förhållanden, dimensioneringsmetodiken och designade typförstärkningslösningar.Rock facilities usually requires some type of rock support. When designing new rock facilities, typical support solutions are used. These are solutions that are repeatable for certain predetermined criteria. The guiding parameters are usually tunnel width and rock quality. Previously built tunnels have resulted in several designed typical support solutions for different conditions. It is therefore advantageous to study how we have previously designed typical support solutions. The purpose of this thesis was to investigate the possibilities of improving the efficiency of designing typical support solutions. A case study was carried out, in which the seven different studied projects were the City Line, the new Metro, the north Bothnian Line, Hallsberg - Stenkumla, the Hamn Line, the Bothnia Line and the Stockholm Bypass. For each project, the geological conditions, the design methodology and the typical support solutions were analyzed.
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Reinhold, Chris. "Ein Beitrag zur Bemessung von Böschungen mit Erdbetonstützscheiben." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2009. http://nbn-resolving.de/urn:nbn:de:bsz:105-5584170.
Full textAbstract:
Die Methode der Böschungsertüchtigung mit Erdbetonstützscheiben ist ein etabliertes Verfahren. In der Vergangenheit entwickelte Bemessungsverfahren für Böschungen mit Stützscheiben konnten sich bis heute nicht durchsetzen. Stattdessen behilft man sich in der Praxis mit einer Art Ersatzverfahren. Mit diesem Verfahren wird die Standsicherheit der Böschung mit Stützscheiben teilweise unzutreffend ermittelt. Dies wird in der Arbeit begründet und anhand von Beispielen verifiziert. Die Tragwirkung der Stützscheiben kann nur durch räumliche numerische Berechnungen ausreichend genau erfasst werden. Es wird eine zwingend erforderliche Typisierung der Stützscheiben bezüglich ihres Tragverhaltens und des Bruchmechanismus durchgeführt. Die erreichbare Stabilisierungswirkung der Stützscheiben hängt wesentlich von der Scheibengeometrie und dem Scheibenabstand ab. In der Arbeit werden für einen Scheibentypen der Versagensmechanismus, das Tragverhalten sowie deren Einflüsse ausführlich analysiert und anschließend ein Bemessungsverfahren hergeleitet. Für weitere Scheibentypen werden Vorschläge für mögliche Bemessungsverfahren angegeben.
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Carletto, Marcos Francisco Wosgrau. "Jet Grouting (sistema monofluido): um método teórico simplificado para a previsão do diâmetro das colunas." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3145/tde-13102009-154059/.
Full textAbstract:
O jet grouting é uma das técnicas de tratamento de solos mais utilizadas em todo o mundo. Consiste em jatear uma calda de cimento a altíssima velocidade no subsolo, com ou sem a adição de água e/ou ar comprimido. Os fluidos são injetados através de minúsculos bicos posicionados na extremidade de uma composição especial de hastes, que giram à velocidade constante enquanto sobem lentamente em direção à superfície do terreno. O jato remove e mistura o solo, produzindo um corpo consolidado de formato aproximadamente cilíndrico (a coluna de jet grouting). Variando os parâmetros operacionais (pressão de bombeamento, quantidade e diâmetro dos bicos, velocidade de extração das hastes, relação água/cimento da calda) e em função do tipo de solo, podem ser obtidas colunas de diâmetros variáveis dentro de um amplo intervalo. Na busca do diâmetro desejado, a escolha dos parâmetros de tratamento é feita atualmente com base em regras empíricas nem sempre pertinentes, causando muitas vezes o fracasso do tratamento ou, ainda, tornando-o excessivamente oneroso. Esta tese de doutorado apresenta um método simplificado para a previsão do diâmetro das colunas de jet grouting (sistema monofluido). Conjugando a análise racional do fenômeno físico de interação jatosolo (Modoni et al., 2006) à facilidade de aplicação característica dos métodos empíricos, propõe-se uma ferramenta ágil para a escolha da combinação mais adequada dos parâmetros de tratamento.Jet grouting is one of the most popular ground improvement techniques all over the world. The method is based on high-speed grouting of water-cement mixtures and/or other fluids (air, water) into the subsoil. The fluids are injected through small diameter nozzles placed on a grout pipe, which is continuously rotated at a constant rate and slowly raised towards the ground surface. The jet removes and mixes the soil, producing a cemented body of quasi-cylindrical shape (the jet grouting column). Varying the operational parameters (grout pressure, number and diameter of the nozzles, monitor lifting rate, water-cement ratio of the grout) and as a function of the soil type, columns of variable diameters can be obtained in a wide interval. Currently, in search of the required diameter, the choice of the operational parameters is done on the basis of empirical rules not always relevant, causing very often the failure of the treatment or making it excessively onerous. This thesis presents a simplificated method for the prediction of the column diameter (single fluid system). Conjugating the rational analysis of the physical phenomenon of jetsoil interaction (Modoni et al., 2006) to the typical easiness of empirical methods application, an agile tool is proposed for the choice of the most appropriate combination of the operational parameters.
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Bartolomeu, Daniel. "Análise da vulnerabilidade dos recursos hídricos na região urbana de São Carlos (SP) por vazamentos em postos de combustíveis, utilizando o método GOD e avaliação dos condicionantes geotécnicos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/18/18132/tde-08112012-112827/.
Full textAbstract:
O constante avanço econômico e tecnológico que estamos vivendo, nos dias de hoje possui como uma das mais marcantes características o aumento na demanda de combustíveis para diversos usos. Fato que pode ser preocupante do ponto de vista ambiental, onde estes combustíveis representam grandes potenciais poluidores. Na área de estudos (região urbana de São Carlos - SP) já existem focos de poluição identificados pela CETESB, onde também ocorrem três importantes aquíferos: Bauru, Guarani (porosos) e Serra Geral (fraturado), estando estes em sessão aflorante (zona de recarga) e em sub-superfície. O mapeamento geológico-geotécnico é uma importante ferramenta, que pode ser empregada como método de diagnóstico fundamentando a análise de vulnerabilidade de contaminação dos recursos hídricos. Com a integração do mapeamento geotécnico e técnicas de caracterização específicas de áreas contaminadas poderemos proceder com uma análise de vulnerabilidade mais consistente. O método GOD, utilizado como parâmetro para a análise de vulnerabilidade, vem sendo muito utilizado tanto no cenário nacional como internacional. Neste trabalho se mostrou eficiente, sendo possível correlacionar as diversas classes de vulnerabilidade com os compartimentos geológico-geotécnicos definidos no mapeamento e com a análise dos condicionantes geotécnicos que podem deflagrar uma contaminação em cada unidade geológico-geotécnica definida.The constant economic and technological advancement that we are living today has one of the most striking features an increase in fuel demand for different uses. This fact may be worrying the environmental point of view, where these fuels are major potential polluters. In the study area (urban area of Sao Carlos - SP) since there are outbreaks of pollution identified by CETESB, where also there are three major aquifers: Bauru, Guarani (porous) and Serra Geral (fractured), the latter being in session outcropping (zone charge) and sub-surface. The geological-geotechnical mapping is an important tool that can be used as a method of diagnosing the reasons for vulnerability analysis of contamination of water resources. With the integration of geologicalgeotechnical mapping and geotechnical characterization techniques to specific contaminated areas can proceed with a more consistent vulnerability analysis. The GOD method, used as a parameter for the vulnerability analysis, has been widely used in both the national and international scenario. In this work This method was successfully, it is possible to correlate the various classes of vulnerability compartments defined in the geological-geotechnical mapping and analysis of geotechnical conditions which may trigger a contamination in each unit defined.
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Kováč, Vladimír. "Analýza násypového tělesa na podloží zlepšeném prefabrikovanými vertikálními drény." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392237.
Full textAbstract:
The thesis deals with the back analysis of the instrumentated embankment on the subsoil, improved by prefabricated vertical drains. The first part is devoted to the theory of consolidation calculation. Furthermore, the author deals with a parametric study of the analytical calculation of prefabricated drains and the comparsion of the analytical and numerical solution. The last and the largest part of the work is a back analysis of the embankment which was built as a part of the subsoil improvement near the Suez Canal in Egypt by Keller GmbH.