Academic literature on the topic 'Seismic Shaking'
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Journal articles on the topic "Seismic Shaking"
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Monastersky, Richard. "Shaking up Seismic Theory." Science News 141, no. 9 (February 29, 1992): 136. http://dx.doi.org/10.2307/3976199.
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Nouchi, E., N. G. Wariyatno, A. L. Han, and B. S. Gan. "Comfort-based Criteria for Evaluating Seismic Strengthening Performance of Building." IOP Conference Series: Earth and Environmental Science 1195, no. 1 (June 1, 2023): 012002. http://dx.doi.org/10.1088/1755-1315/1195/1/012002.
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Abstract In modern seismic design and technologies, the building’s seismic-resistant based on non-collapse plastic deformation. According to the periodical reports of the Japan Meteorological Agency, the number of people injured due to strong earthquakes is much higher than the number of deaths. Also, the number of buildings collapsed is less than the partly damaged buildings. The report also concludes that human injuries or deaths are not a result of the collapsed building. Human injuries or deaths are due to shakings when strong earthquakes strike the building. The cause of human casualties is the collapse of non-structural elements such as ceilings, bookshelves, or machinery appliances. The report implies that the buildings designed by the latest revised seismic standards have good earthquake resistance but fail to protect human casualties. Present works proposed comfort-based criteria for evaluating the quantitative shaking of buildings. The use of comfort-based criteria is demonstrated in evaluating the strengthening case studies selection processes. The study revealed that, in general, the seismic strengthening of a building by using bracings is not effective in reducing the shaking of the building. The proposed method highly recommends using shaking quantity criteria as an evaluation tool in the seismic strengthening design of buildings to select the best output in decision-making.
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Xianfeng, Ma, Wang Guobo, Wu Jun, and Ji Qianqian. "Experimental Study on the Seismic Response of Subway Station in Soft Ground." Journal of Earthquake and Tsunami 11, no. 05 (December 2017): 1750020. http://dx.doi.org/10.1142/s1793431117500208.
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Shaking table tests were conducted on typical models of subway structures subjected to several seismic shaking time histories to study seismic response of subway structures in soft ground as well as to provide data for validation of seismic design methods for underground structure. Three types of tests were presented herein, namely green field test, subway station test, and test for joint structure between subway station and tunnel. The similitude and modeling aspects of the 1g shaking table test are discussed. The seismic response of Shanghai clay in different depths was examined under different input waves to understand the acceleration amplification feature in both green field and in the presence of underground structure. Damage situation was checked on internal sections of both subway station and tunnels by halving the model structure. Structure deformation was investigated in terms of element strain under different earthquake loadings. The findings from this study provides useful pointers for future shaking table tests on underground structures/facilities, and the seismic response characteristic of underground structure derived from the shaking table test could be helpful for validating seismic design method for subway station.
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Huang, Fu Yun, Zi Ming Fang, and Jian Zhong Li. "Performance of Earthquake Simulation Three Bi-Axial Shaking Tables." Applied Mechanics and Materials 518 (February 2014): 178–83. http://dx.doi.org/10.4028/www.scientific.net/amm.518.178.
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The shaking tables array is the prospective development direction in engineering structural anti-seismic researching field, and which can provide a powerful seismic testing platform. In this paper, the performance of three bi-axial shaking tables array at Fuzhou University was introduced. The trails of bare tables, fully inertial payload shaking tables as well as partly payload shaking tables with elastic structures were conducted. The testing reveals that the shaking tables array system of Fuzhou University has a perfect performance of compliance, coherence and synchronization, which are accepted the required.
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Dai, Jian-Bo, Gui-Di Zhang, Cheng-Tao Hu, and Kai-Kai Cheng. "Study on Synthesis Method of Multipoint Seismic Waves for Buried Oil and Gas Pipeline in Shaking Table Tests." Shock and Vibration 2021 (July 31, 2021): 1–8. http://dx.doi.org/10.1155/2021/4624871.
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The buried oil and gas pipeline is a linear structure with infinite length. In the shaking table test of its seismic response, it is necessary to input the spatially related multipoint seismic wave considering the propagation characteristics of ground motion. The multipoint seismic excitation shaking table tests and loading scheme of buried oil and gas pipelines are designed and formulated. The synthesis method of spatial correlation multipoint seismic wave for the buried oil and gas pipeline test is proposed in this study. The values of relevant parameters are analyzed, and corresponding program is compiled by MATLAB. The results show that the developed multipoint excitation shaking table seismic wave input scheme is reasonable. At the same time, the synthesized multipoint seismic wave based on the actual seismic record and artificial random simulation seismic wave can meet the test requirements, which suggests the testing effect is good.
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Mesri, Gholamreza, Marawan Shahien, and Thierno Kane. "Seismically induced settlement of ground experiencing undrained shaking and laterally constrained compression." Canadian Geotechnical Journal 56, no. 2 (February 2019): 155–72. http://dx.doi.org/10.1139/cgj-2017-0419.
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A method is proposed for estimating seismically induced settlement of saturated sands experiencing undrained shaking and laterally constrained compression. An empirical relationship is developed between the seismic coefficient of vertical compression, mvs, and standard penetration test blow count, N60, as a function of factor of safety against liquefaction, Fℓ, based on data interpreted from 18 sets of laboratory cyclic direct simple shear tests and 23 cases of field observations of seismic liquefaction. The proposed method is compared with seismic settlement observed at 78 sites subjected to 7.1–8.0 magnitude earthquakes, and with predictions by the previous well-known methods of settlement analysis for undrained shaking. For silty–clayey sands, the significant effect of the plasticity of fines on seismic settlement is illustrated. The use of pre- or post-earthquake penetration resistance for back-analyses of field seismic settlement observations is examined. A tentative correction factor is suggested for seismic settlement estimated based on the assumption of undrained shaking and laterally constrained compression for liquefied saturated sublayers at small distances from drainage boundaries or under buildings with small breadths, which may experience volumetric compression during ground shaking.
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Berril, J. B., R. O. Davis, and I. F. McCahon. "Christchurch seismic hazard pilot study." Bulletin of the New Zealand Society for Earthquake Engineering 26, no. 1 (March 31, 1993): 14–27. http://dx.doi.org/10.5459/bnzsee.26.1.14-27.
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A pilot zoning study has been carried out for ground shaking hazard in the city of Christchurch, using the grade-3 procedures of the draft manual on seismic zonation for geotechnical hazards, being developed by Technical Committee TC-4 of the ISSMFE. Because of limited site data, we were not able to produce a complete zoning map for the city, but ground motions were estimated at six distinct sites for which borehole data was available, and this provided a good test for the procedures of the manual.
The city of Christchurch is situated on nearly 1 km of volcanic rock and alluvial sediments overlying greywacke basement, on the edge of the main seismic region of New Zealand. In addition to being an interesting site from the point of view of ground shaking, there are also liquefaction and slope stability hazards in the alluvial and beach sands found throughout the city, and in the recent loess deposits mantling the adjacent Port Hills.
In the pilot study of ground shaking hazard, a seismicity model for the central South Island region published recently by Elder et al. (1991) was combined with the attenuation model of Kawashima et al. (1984) recommended in the draft manual, to estimate rock motion at Christchurch, described by its acceleration response spectrum. Transfer functions were computed for the site response to estimate motions at the six selected sites using the Thomson-Haskell method. The results were highly sensitive to details of. the upper 30 m or so of the soil profile. In the local context, the large disparity between our estimates of ground shaking at Christchurch and those implicit in the draft revision of NZS 4203 are disturbing. According to our study the draft code underestimates shaking by about a factor of two or more.
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Xiong, Wei, Ming Ren Yan, and Yao Zhuang Li. "Geotechnical Seismic Isolation System - Further Experimental Study." Applied Mechanics and Materials 580-583 (July 2014): 1490–93. http://dx.doi.org/10.4028/www.scientific.net/amm.580-583.1490.
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The isolation effectiveness of the Geotechnical Seismic Isolation (GSI) system was further investigated via a series of prescribed shaking-table tests. The dynamic response of GSI system was also evaluated in detail of this work. A parametric study for assessment of the isolation performance of GSI was conducted by varying experimental key parameters, such as rubber percentage of rubber-sand mixtures (RSM), configuration of the foundation, storey number of the superstructure, and different kinds of seismic acceleration inputs. From the parametric survey, it can be concluded that the GSI system can to some extent attenuate the dynamic response of the superstructure under big earthquake shakings.
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Akers, Stuart W., and Cary A. Mitchell. "Seismic Stress Effects on Reproductive Structures of Tomato, Potato, and Marigold." HortScience 20, no. 4 (August 1985): 684–86. http://dx.doi.org/10.21273/hortsci.20.4.684.
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Abstract Periodic seismic (shaking) stress influenced the growth of sexual and asexual reproductive structures of three cultivated species. It delayed anthesis of Lycopersicon esculentum Mill. ‘Patio’ but not of Tagetes erecta L. ‘Jubilee’ or Solanum tuberosum L. ‘Kennebec’. Shaken ‘Jubliee’ marigold plants produced the same number of flowers as undisturbed plants, but flowers of shaken plants were smaller. In contrast, seismicstressed ‘Patio’ tomato produced fewer buds and flowers, but fruit set was enhanced relative to that of controls. Seismic stress also reduced tuber weight of ‘Kennebec’ potato, whereas tuber number was unaffected. The overall effect of seismic stress was to reduce the growth of reproductive structures and, in some cases, the number of reproductive structures that developed.
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Towhata, Ikuo, Md Jahangir Alam, Tsuyoshi Honda, and Satoshi Tamate. "Model tests on behaviour of gravity-type quay walls subjected to strong shaking." Bulletin of the New Zealand Society for Earthquake Engineering 42, no. 1 (March 31, 2009): 47–56. http://dx.doi.org/10.5459/bnzsee.42.1.47-56.
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Seismic stability of gravity-type quay walls and prevention of their large distortion are of major concern from a disaster prevention view point as well as in the sense of successful restoration after strong seismic events. There are, however, many existing walls which are of limited seismic resistance and would not be safe under increasing magnitude of design earthquakes. The present study conducted shaking model tests in both 1-g and 50-g centrifugal fields in order to demonstrate the efficiency of available mitigation technologies. Test results suggest that soil improvement in the loose foundation sand can reduce the quay wall damage to a certain extent when the intensity of shaking is around 0.30g. In contrast, under stronger shaking, the centrifugal tests manifested that those measures are not promising because of the increased effects of seismic inertia force.
Dissertations / Theses on the topic "Seismic Shaking"
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Manasseh, Mazen 1980. "A web-controllable shaking table for remote structural testing under seismic loading." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/29382.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2004."June 2004."
Includes bibliographical references (leaf 73).
The thesis presents a remotely accessible system for controlling a shaker table laboratory experiment. The Shake Table WebLab is implemented at MIT's Civil Engineering Department under the Microsoft-sponsored iLab initiative for the development of educationally-oriented virtual experiments. Facilitated accessibility, safe operation and expandability are essentials at the root of the design and implementation of the Shake Table WebLab. The fully functional system allows students and researchers to excite a two-story structure, which is three feet high, by vibrating its base while receiving accelerometer readings from its three levels. Registered Internet users may upload their own input data, such as the seismic ground acceleration of a newly occurring earthquake, and therefore study the corresponding behavior of a real structure. The system is designed with an expandable architecture which enables future researchers to add functionalities that suit their fields of interest. Relevant fields of study include real-time signal processing and filtering techniques that would provide an understanding of how earthquakes affect a structure and therefore provide insight on means to minimize encountered damage in large-scale structures. An already developed tool utilizes frequency domain transfer functions to compare the measured structural response at the upper levels with a predictable result based on seismic vibrations applied at the structure's base. Two main characteristics of the web-based application are interactivity, provided through synchronized control/response processes, and sensor-based monitoring of the experiment.
(cont.) The system is built on the Microsoft .Net Framework through server-hosted Active Server Pages and browser-embedded Windows Form Controls. Web Service methods are implemented for initiating remote processes. Throughout the thesis, I state the motivations for conducting this project, the different online activities and generic administrative features, and a description of the implemented technologies and system components.
by Mazen Manasseh.
S.M.
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Kong, Fanchen 1964. "Analysis of lichen-size data for dating and describing prehistorical seismic shaking." Thesis, The University of Arizona, 1994. http://hdl.handle.net/10150/558237.
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Kalpakci, Volkan. "Seismic Isolation Of Foundations By Composite Liners." Phd thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615500/index.pdf.
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In this research, the dynamic behavior of a seismic isolation system composed of high strength geotextile placed over an ultra-high molecular weight polyethylene (UHMWPE) geomembrane (together called as composite liner) beneath the structure is investigated experimentally. The results of the shaking table experiments which were performed on model structures both under harmonic and modified earthquake motions with and without the seismic isolation (composite liner system), are presented in the thesis. The main focus is given on the potential improvement obtained by use of the composite liner system as compared to the unisolated cases. Based on the performed experiments, it is observed that the utilization of composite liner system provides significant reduction in the accelerations and interstorey drift ratios of structures under harmonic motions while signifant drop is obtained in the spectral accelerations under earthquake motions which provide noticeable improvement in the durability of structures under dynamic effects at the expense of increased translational displacements.
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Yavari, Soheil. "Shaking table tests on the response of reinforced concrete frames with non-seismic detailing." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/32155.
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Reinforced concrete frames constructed before the introduction of modern seismic codes have performed poorly during past earthquakes. Such frames have primarily been designed for gravity load effects, leading to light transverse reinforcement in the columns, unconfined beam-column joints, and generally a lack of seismic details required for ductile post-yield behaviour. It has been demonstrated in literature that light transverse reinforcement in a column may result in shear and axial failure. Furthermore, lack of confinement may cause shear failure at joints. However, interaction of vulnerable components and their contribution to the collapse behaviour of existing reinforced concrete frames is not well understood. This research project was initiated to provide a better understanding of the factors contributing to collapse of the frames with non-seismic detailing.
In the experimental phase of this study, four 1:2.25 scale, two-bay-two-story specimens were designed with non-seismic details and tested on a shaking table. The target failure mode was intended to be damage leading to collapse that would enable examination of gravity load redistribution during the test. The tests provide unique benchmark data for both qualitative and quantitative assessment of the factors influencing the behaviour of reinforced concrete frames up to the point of collapse. Based on the results from the shaking table tests, this dissertation will evaluate the influence of axial load on shear and axial behaviour of non-ductile columns and the effects of unconfined joints on overall behaviour of a frame near the point of collapse.
The analytical phase of the research included evaluation of existing models for predicting shear and axial failure of non-ductile columns and collapse of frames. The currently available models for shear and axial failure of non-ductile columns are mainly drift-based. The results of the current study suggest that these models should be refined using the column ends rotation demand. While results from comprehensive nonlinear models of the four specimens were compared with the test data, simplified models that can be easily employed in engineering practice for assessing existing frames were also evaluated. A refinement to provision from ASCE-41 on column effective stiffness was also proposed in this dissertation.
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CASTIGLIA, Massimina. "The experimental study of buried onshore pipelines seismic-liquefaction induced vertical displacement in shaking table tests and its remedial measures." Doctoral thesis, Università degli studi del Molise, 2019. http://hdl.handle.net/11695/90945.
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Il fenomeno di liquefazione sismo-indotta dei terreni può causare danni rilevanti alle strutture interrate. Nella progettazione di tubazioni interrate non è sempre possibile evitare le zone ad elevata sismicità con un alto rischio di liquefazione. Questo aspetto è evidente se si pensa alla lunghezza dei tracciati e all’estensione sul territorio, legata alla necessità di garantire l’approvvigionamento di servizi essenziali in maniera diffusa. Nello specifico, le tubazioni costituiscono un mezzo di trasporto per fluidi di varia natura, dal petrolio greggio al gas naturale, dall’acqua alle acque reflue. La progettazione di queste strutture è complessa e necessita di tenere debitamente in conto i rischi naturali e le relative conseguenze.
Tra le diverse manifestazioni associate al fenomeno, in caso di tubazioni leggere quali ad esempio le tubazioni per il trasporto di gas naturale, può verificarsi una risalita del tubo. Casi di risalita di tubazioni interrate si sono avuti ad esempio in occasione del terremoto di Kushiro-Oki nel 1993, del terremoto di Hokkaido-Toho-Oki nel 1994, del terremoto di Niigata nel 2004 o del terremoto di Tohoku nel 2011. Manifestazioni di liquefazione con conseguenti danni alle infrastrutture interrate si sono avuti durante la sequenza sismica di Christchurch del 2010-2011, inoltre, ingenti perdite di gas da tubazioni interrate con conseguente innesco e propagazione di incendi si sono osservati con il terremoto di Kobe nel 1995.
Le metodologie tradizionali per contrastare gli effetti del fenomeno di liquefazione sono state ampiamente utilizzate e sono sufficientemente consolidate in termini di implementazione e risultati. Tuttavia, la loro efficacia nella mitigazione della liquefazione per i problemi specifici legati alle condotte interrate non è altrettanto consolidata. In linea generale, le tecnologie e i materiali attualmente in fase di studio sembrano fornire risultati promettenti per applicazioni future ma non esistono ancora, ad oggi, soluzioni standardizzate. Nella proposta di opportune metodologie di mitigazione che facciano fronte al problema della risalita, bisogna considerare diversi fattori quali, ad esempio, la variabilità delle caratteristiche dei terreni attraversati, il tempo necessario alla soluzione adottata per diventare efficace in sito, nonché la sua durabilità in rapporto alla vita nominale dell’opera, quantità e costo dei materiali e semplicità di realizzazione e installazione.
Questa attività di ricerca si pone l’obiettivo di esplorare soluzioni alternative per il problema specifico di risalita delle condotte interrate che si verifica in caso di liquefazione sismo-indotta. La ricerca è stata sviluppata presso il laboratorio di geotecnica dell’Università di Tokyo, mediante prova su tavola vibrante effettuate su modelli in scala 1:10. Questa tesi illustra i risultati di undici prove, eseguite durante due periodi distinti di permanenza all’estero. Le prove sono incentrate sullo studio del comportamento della sezione trasversale del tubo, in un deposito di terreno sabbioso mediamente addensato, all’applicazione di una serie di storie temporali sinusoidali di accelerazione. Alcune delle prove sono basate sulla quantificazione dello spostamento verticale del tubo in relazione al diverso peso apparente, le restanti prove mirano invece allo studio delle metodologie di mitigazione per la stabilità del sistema. Tubi drenanti, sacco di ghiaia e geogriglie sono stati utilizzati come metodologie di mitigazione durante la sperimentazione. Un sacco di ghiaia disposto al di sopra della tubazione è risultato soddisfacente nella mitigazione della risalita. Questo sistema rappresenta una soluzione alternativa a basso costo e semplicità di realizzazione e posa in opera, indipendentemente dalle caratteristiche del terreno del sito specifico e che può essere utilizzata con l’ulteriore beneficio di un eventuale drenaggio dell’acqua grazie alle caratteristiche di permeabilità dei materiali ghiaiosi.Liquefaction of soil deposit can impose deformations on the structures interacting with it with consequent damages. In the design of lifelines, it is not always possible to avoid areas with high seismicity in which the liquefaction hazard is consistent, due to the very long route of these infrastructures and the necessity to provide essential services in different areas. Specifically, pipeline systems provide a medium of transportation for fluids which could vary from crude oil or natural gas to water or sewage fluids. Their construction is challenging due to natural hazards that might cause loss of functionality and possible danger to the environment. The loss of soil shear strength can produce permanent ground deformation which can lead to lateral movements, flotation or subsidence of buried pipeline in case of liquefaction. Uplift of underground structures might also occur, mostly in case of very light structures which could be the pipelines transporting natural gas. Numerous cases of uplift of buried pipelines have been observed over years for example during the 2004 Niigata Earthquake, the 2011 Tohoku Earthquake, 1993 Kushiro-Oki Earthquake and 1994 Hokkaido-Toho-Oki Earthquake. In addition, the 2010-2011 Christchurch Earthquake sequence induced liquefaction on a vast area and massive damage to buried infrastructure has been accounted for. Kobe Earthquake in 1995 caused extensive gas leakage from buried pipelines with subsequent fires ignition. Conventional methods to prevent liquefaction have been widely used worldwide and are enough consolidated in terms of implementation and results but their effectiveness in the mitigation of liquefaction for buried pipelines is less known. Different solutions have been investigated over years to assess this problem and recently new techniques are developing to satisfy engineering economy, environmental impact, technical performances and durability criteria. For the specific problem of pipelines, various aspects need to be considered such as different soils characteristics for the length of the pipeline track, time for the solution to start being effective on site, life of the solution when compared with the design life of the pipe, amounts and costs of the materials and simplicity of realization. Overall new technologies and new materials seem to have satisfactory results promising for future applications but there are not yet solutions which can be considered as a standard. To assess this specific problem, accounting for all the above-mentioned factors, this research work wants to investigate alternative solutions for the specific problem of seismic-liquefaction induced uplift of onshore gas buried pipelines. The research is conducted by means of 1-g shaking table tests in a model scale of 1:10 performed in the geotechnical laboratory of the University of Tokyo. This thesis presents the results of eleven shaking table tests, executed in two different time periods, with reference to the transversal cross-section of the pipe embedded in a homogenous medium-dense sandy soil deposit by applying series of input motion. Some of the tests deal with the quantification of the vertical displacement by changing the pipe apparent unit weight and the remaining tests study the effectiveness of new remedial measures to increase the stability of the system. Drain pipes, gravel bags, and geogrids are used as testing countermeasures and the experimental results will be presented in the thesis. A gravel bag installed above the pipeline has been proven effective in mitigating the uplift. This represents an innovative protection system with low-cost technology and easiness of realization and installation in every kind of soil condition and which can be used with the support of the additional benefit of drainage systems not accounted for in this research. Please note that this thesis does not provide considerations on the longitudinal development of the pipelines, which would have required specific studies.
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Ryan, John C. "Analytical and Experimental Investigation of Improving Seismic Performance of Steel Moment Frames Using Synthetic Fiber Ropes." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/29392.
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The presented research investigated the viability of a double-braided synthetic fiber rope for providing improved performance of steel moment frames subjected to earthquake-induced ground motions. A series of experimental tests, including a 1:3-scale dynamic test and 1:6-scale shaking table tests, was conducted using Northridge ground-motion input. A series of nonlinear dynamic analytical studies, using DRAIN-2DX, was conducted to develop the experimental tests.
Throughout experimental testing, the ropes exhibited a hyper-elastic loading response and a reduced-stiffness unloading response. A conditioning cycle was defined as a loading cycle induced in the rope above the highest load expected to be experienced by the rope, and was determined to be requisite for ropes intended to be used for the stated objectives of the research program. After experiencing a conditioning cycle, the rope response returned to initial conditions without permanent deformation, demonstrating repeatability of response through several loading cycles below the conditioning load.
In the 1:6-scale shaking-table experiments, the ropes drastically improved the performance of the steel moment frames. Maximum and residual drift were reduced significantly, with a corresponding minimal increase to the maximum base shear. Base shear was reduced at several peaks subsequent to the initial pulse of the Northridge ground-motion input.
The analytical model developed was excellent for predicting elastic response of the 1:6-scale shaking table experiments and adequate for the purpose of planning shaking table studies. Correlation of peak rope forces between the analytical model and experimental results was poor, and was attributed to limitations of the pre-defined elements used to represent the rope devices in the software program. The inability of the elements to capture the complex unloading response of the rope was specifically noted.Ph. D.
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Nizamiev, Kamil. "Simulation, Analysis and Design of Systems with Multiple Seismic Support Motion." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1462884476.
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Goy, Cristina. "Displacement Data Processing and FEM Model Calibration of a 3D-Printed Groin Vault Subjected to Shaking-Table Tests." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20061/.
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The present thesis is part of the wide work required by the SEBESMOVA3D (SEeismic BEhavior of Scaled MOdels of groin VAults made by 3D printers) project whose first motivation is the preservation of the cultural heritage in case of seismic events.
Therefore, the main topic of the thesis is the analysis of the seismic response of scaled models of groin vaults, made of plastic 3D printed bricks filled with mortar, and subjected to shaking table tests performed at the EQUALS laboratory of the University of Bristol. The work has been developed on two parallel binaries: the processing of the displacement data acquired in situ and the calibration of a FEM model.
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Singh, Bina Aruna. "GIS based assessment of seismic risk for the Christchurch CBD and Mount Pleasant, New Zealand." Thesis, University of Canterbury. Geography, 2006. http://hdl.handle.net/10092/1302.
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This research employs a deterministic seismic risk assessment methodology to assess the potential damage and loss at meshblock level in the Christchurch CBD and Mount Pleasant primarily due to building damage caused by earthquake ground shaking. Expected losses in terms of dollar value and casualties are calculated for two earthquake scenarios. Findings are based on: (1) data describing the earthquake ground shaking and microzonation effects; (2) an inventory of buildings by value, floor area, replacement value, occupancy and age; (3) damage ratios defining the performance of buildings as a function of earthquake intensity; (4) daytime and night-time population distribution data and (5) casualty functions defining casualty risk as a function of building damage. A GIS serves as a platform for collecting, storing and analyzing the original and the derived data. It also allows for easy display of input and output data, providing a critical functionality for communication of outcomes. The results of this study suggest that economic losses due to building damage in the Christchurch CBD and Mount Pleasant will possibly be in the order of $5.6 and $35.3 million in a magnitude 8.0 Alpine fault earthquake and a magnitude 7.0 Ashley fault earthquake respectively. Damage to non-residential buildings constitutes the vast majority of the economic loss. Casualty numbers are expected to be between 0 and 10.
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Zuccolo, Elisa. "Neo-deterministic seismic hazard scenarios: from the modelling of the past to prediction." Doctoral thesis, Università degli studi di Trieste, 2010. http://hdl.handle.net/10077/3489.
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2008/2009È stato affrontato il problema della definizione della pericolosità sismica utilizzando il metodo neo-deterministico (NDSHA), che si basa sul calcolo di sismogrammi sintetici realistici. Considerando modelli strutturali medi e un set di sorgenti distribuite internamente alle zone sismogenetiche, possono essere definite delle mappe di scuotimento al bedrock complementari alla mappa di pericolosità di tipo probabilistico (PSHA) sulla quale è basata la normativa antisismica italiana. L’analisi di stabilità effettuata ha dimostrato che l’informazione disponibile sui terremoti del passato può non essere rappresentativa per i futuri terremoti, anche se si hanno a disposizione cataloghi estesi nel tempo (∼ 1000 anni). Ciò non è sorprendente se si tiene presente la scala dei tempi dei processi geologici, ma tale consapevolezza è spesso ignorata in PSHA. NDSHA permette di superare questo limite mediante l’uso di indicatori indipendenti sul potenziale sismico di un’area (e.g. nodi sismogenetici e faglie attive) che consentono di colmare le lacune nella sismicità osservata. Il confronto tra le mappe di pericolosità PSHA e NDSHA sul territorio italiano ha evidenziato che NDSHA fornisce valori maggiori di PSHA nelle aree caratterizzate da forti terremoti osservati e in corrispondenza dei nodi sismogenetici. I valori massimi di NDSHA sono confrontabili con quelli di PSHA per lunghi periodi di ritorno (T≥2475 anni). D’altro canto, PSHA tende a sovrastimare, rispetto a NDSHA, la pericolosità sismica in aree a bassa sismicità. È quindi auspicabile una revisione della normativa che tenga conto di questi fatti. Gli scenari di scuotimento sono utili sia per la ricostruzione delle caratteristiche di sorgente dei terremoti del passato (es. terremoto del 1117) che per la previsione degli effetti degli eventi futuri. Quest’ultimo aspetto, importante per le azioni di prevenzione della Protezione Civile, è stato sviluppato nell’ambito del progetto ASI-SISMA mediante la generazione di scenari dipendenti dal tempo a diversa scala di dettaglio. L’applicazione della tecnica analitica di calcolo dei sismogrammi sintetici in mezzi anelatici tridimensionali, per la cui è stata messa a punto una subroutine per la gestione automatica dell’input, è stata applicata allo studio di eventi di profondità intermedia, avvenuti in Vrancea (Romania), considerando sia serie temporali registrate (accelerogrammi) che intensità osservate.
The problem of the definition of the neo-deterministic seismic hazard assessment (NDSHA), based on the computation of realistic synthetic seismograms, has been capably addressed. Considering average structural models and a set of sources distributed within the seismogenic zones, ground shaking maps at the bedrock, complementary to the probabilistic seismic hazard (PSHA) map on which the Italian seismic code is based, can be defined. The stability analysis performed showed that the available information from past events may not be well representative of future earthquakes, even if long earthquake catalogues (< 1000 years) are available. This is not surprising if we consider the geological times, but this awareness is often ignored in PSHA. NDSHA can easily overcome this limit since it allows to take into account, in a formally well defined way, not only the observed seismicity but also independent indicators of the seismogenic potential of a given area like the seismogenic nodes and active faulting data. The comparison between PSHA and NDSHA maps over the Italian territory evidenced that NDSHA provides values larger than those given by PSHA in areas where large earthquakes are observed and in areas identified as prone to large earthquakes (i.e. seismogenic nodes). The maximum values of NDSHA are consistent with those of PSHA for long return periods (T≥2475 years). Comparatively smaller values are obtained in low-seismicity areas. Therefore a revision of the code taking into account these facts is desirable. Ground shaking scenarios are useful in order to detect the main characteristics of the past earthquakes (e.g. the 1117 earthquake) and to predict the expected ground shaking associated with future earthquakes. The last aspect, which constitutes a useful tool for the rescue actions of the Civil Protection, has been developed in the framework of the ASI-SISMA Project by means of the generation of multi-scale time-dependent seismic hazard scenarios. The application of the analytical technique for the computation of synthetic seismograms in three-dimensional anelastic models, for which a subroutine for the automatic generation of the input has been developed, has been applied to the study of intermediate-depth Vrancea (Romania) earthquakes, considering both recorded time series (accelerograms) and observed macroseismic intensities.
XXII Ciclo
1982
Books on the topic "Seismic Shaking"
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Geological Survey (U.S.), ed. The TREMOR Project, earthquake-shaking "Radar" for the City of Oakland: A guide for users, sponsors, and the curious. [Menlo Park, CA]: U.S. Dept. of the Interior, U.S. Geological Survey, 1998.
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Zampieri, Andrea. Seismic Behavior Analysis of Concrete Highway Bridges Based on Field Monitoring and Shaking Table Test Data. [New York, N.Y.?]: [publisher not identified], 2015.
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Bernardo, Calif ). Workshop on Improved Characterization of Strong Ground Shaking for Seismic Design (1997 Rancho. Proceedings: Workshop on Improved Characterization of Strong Ground Shaking for Seismic Design , July 30-31, 1997, Rancho Bernardo, California. Redwood City, Calif: Applied Technology Council, 1999.
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Sykes, Lynn R. Plate Tectonics and Great Earthquakes: 50 Years of Earth-Shaking Events. Columbia University Press, 2019.
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Plate Tectonics and Great Earthquakes: 50 Years of Earth-Shaking Events. Columbia University Press, 2019.
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The TREMOR Project, earthquake-shaking "Radar" for the City of Oakland: A guide for users, sponsors, and the curious. [Menlo Park, CA]: U.S. Dept. of the Interior, U.S. Geological Survey, 1998.
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The TREMOR Project, earthquake-shaking "Radar" for the City of Oakland: A guide for users, sponsors, and the curious. [Menlo Park, CA]: U.S. Dept. of the Interior, U.S. Geological Survey, 1998.
Find full textBook chapters on the topic "Seismic Shaking"
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Saouma, Victor E., and M. Amin Hariri-Ardebili. "Seismic Hazard Analysis." In Aging, Shaking, and Cracking of Infrastructures, 549–75. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-57434-5_23.
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Severn, R. T. "The European shaking table collaborative programme." In European Seismic Design Practice, 27–33. London: Routledge, 2022. http://dx.doi.org/10.1201/9780203756492-5.
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Bourahla, N., and A. Blakeborough. "Shaking table earthquake response of medium-rise knee braced frames." In European Seismic Design Practice, 577–82. London: Routledge, 2022. http://dx.doi.org/10.1201/9780203756492-86.
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Blondet, Marcial, Nicola Tarque, Francisco Ginocchio, and Gladys Villa-García. "Shaking Table Testing of Adobe Masonry Structures." In Structural Characterization and Seismic Retrofitting of Adobe Constructions, 121–51. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-74737-4_6.
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Taylor, C. A., C. Ndamage, and A. Blakeborough. "Shaking table studies of the out-of-plane behaviour of masonry infill." In European Seismic Design Practice, 455–61. London: Routledge, 2022. http://dx.doi.org/10.1201/9780203756492-68.
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Jalilian, Hadis, Jian Hua Yin, and Ali Komak Panah. "Shaking Table Investigation of Seismic Performance of Micropiles." In Proceedings of GeoShanghai 2018 International Conference: Advances in Soil Dynamics and Foundation Engineering, 138–47. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-0131-5_16.
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Madhavi Latha, G., A. Murali Krishna, G. S. Manju, and P. Santhana Kumar. "Geosynthetics in Retaining Walls Subjected to Seismic Shaking." In Latest Developments in Geotechnical Earthquake Engineering and Soil Dynamics, 359–72. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-1468-2_15.
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Sepulveda, Claudio, Ricardo Bustamante, and Gilberto Mosqueda. "Seismic Performance of Isolated Bridges Under Extreme Shaking." In Lecture Notes in Civil Engineering, 447–54. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-21187-4_37.
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Casirati, Mario, Giorgio Franchioni, and Stathis N. Bousias. "Seismic tests on three shaking tables of a 1:8 irregular bridge model." In European Seismic Design Practice, 101–8. London: Routledge, 2022. http://dx.doi.org/10.1201/9780203756492-16.
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Crewe, A. J., A. Simonelli, and A. Scotto di Santolo. "Shaking table tests of scale models of gravity retaining walls." In Seismic Design Practice into the Next Century, 187–94. London: Routledge, 2022. http://dx.doi.org/10.1201/9780203740026-26.
Full textConference papers on the topic "Seismic Shaking"
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Luan, Qiangli, Zhangwei Chen, and He Mao. "Research on Three-Variable Control Technology of Seismic Simulating Shaking Tables." In 8th FPNI Ph.D Symposium on Fluid Power. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fpni2014-7811.
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The seismic simulating shaking table is a typical electro-hydraulic servo test system and is controlled by a servo valve. The test system is widely used in the structural anti-seismic test. The seismic simulating shaking table usually has a low frequency response and a low damping which greatly limit its application for the wide bandwidth test. To further expand the bandwidth of the seismic simulating shaking table and increase its damping TVC (three-variable control) algorithm is proposed. In this paper, we research the TVC (three-variable control) algorithm for the seismic simulating shaking table, and also analyze its correction actions on the system characteristics of the shaking table achieved by both the TVC feedback and TVC feedforward loops. Then we further verify the improvement effects on the system’s frequency response characteristics of the shaking table taken by the TVC algorithm. The algorithm can expand the system bandwidth by introducing a velocity feedback and can increase the system damping by introducing an acceleration feedback. The TVC feedforward loop can eliminate the system poles near to the imaginary axis of system’s closed-loop transfer function and can also further expand the system bandwidth. Finally, we conduct two types of tests on a seismic simulating shaking table: sine sweep tests and seismic waveform replication tests. The results of the sine sweep tests show that the TVC algorithm can effectively improve the system’s frequency response characteristics of the shaking table and also improve its response speed. And the results of the seismic waveform replication tests show that the TVC algorithm can improve the replication accuracy of the seismic waveform.
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Latečki, Helena, Josip Stipčević, and Irene Molinari. "Seismic shaking scenarios for city of Zagreb, Croatia." In 1st Croatian Conference on Earthquake Engineering. University of Zagreb Faculty of Civil Engineering, 2021. http://dx.doi.org/10.5592/co/1crocee.2021.138.
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Castellano, Maria Gabriella, Francesco Balducci, Rodolfo Antonucci, Adolfo Santini, and Nicola Moraci. "Shaking Table Tests on R.C. Frame with Dissipative Bracings." In 2008 SEISMIC ENGINEERING CONFERENCE: Commemorating the 1908 Messina and Reggio Calabria Earthquake. AIP, 2008. http://dx.doi.org/10.1063/1.2963757.
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Julca Calua, Jorge, Deysi Margot Ríos Jiménez, Violeta Zarela Quevedo, Yoner Jaime Romero Cueva, and Marlon Walter Valderrama Puscan. "SEISMIC SHAKING IN ADJACENT REINFORCED CONCRETE STRUCTURES, CAJAMARCA - 2022." In 2nd LACCEI International Multiconference on Entrepreneurship, Innovation and Regional Development (LEIRD 2022): “Exponential Technologies and Global Challenges: Moving toward a new culture of entrepreneurship and innovation for sustainable development”. Latin American and Caribbean Consortium of Engineering Institutions, 2022. http://dx.doi.org/10.18687/leird2022.1.1.42.
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Mao, Dejun. "Structure Seismic Design and Shaking Table Experiment Research Status." In 2017 2nd International Conference on Civil, Transportation and Environmental Engineering (ICCTE 2017). Paris, France: Atlantis Press, 2017. http://dx.doi.org/10.2991/iccte-17.2017.20.
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Sato, Eiji, Tomoyoshi Kakegawa, Taku Suzuki, Koichi Kajiwara, Yasutaka Tagawa, and Shigemitsu Takai. "Alternative Control Design Approach to Shaking Facilities for Re-Creating Seismic Motion." In ASME 2002 Pressure Vessels and Piping Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/pvp2002-1399.
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The 3-D Full-Scale Earthquake Testing Facility (E-Defense) is now under construction in Miki City near Kobe. When completed, the facility will have a 750-ton shaking table measuring 20m by 15m, with a maximum load mass of 1200 tons. It will be able to create vibration in three dimensions with six degrees of freedom. However, the test model considered for this facility has a mass of 1200 tons compared to the shaking table mass of 750 tons, i.e., 1.6 times as heavy as the shaking table and much larger than ordinary test models. In addition, the vibration characteristics change considerably during the experiment due to the damage done to the test weight. Therefore, a better control design is urgently needed in order to overcome these problems. This research suggests a control method that will reproduce the earthquake wave accurately on the shaking table and will consider the robustness. Moreover, we will verify its efficiency by performing a control experiment using an existing two–dimensional, three-degree-of-freedom small shaking table, to which this control method is applied.
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"Assessment of ASCE/SEI 41 Concrete Column Provisions using Shaking Table Tests." In SP-297: Seismic Assessment of Existing Reinforced Concrete Buildings. American Concrete Institute, 2014. http://dx.doi.org/10.14359/51686899.
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De Canio, Gerardo, Giuseppe Muscolino, Alessandro Palmeri, Massimo Poggi, Paolo Clemente, Adolfo Santini, and Nicola Moraci. "Shaking Table Tests Validating Two Strengthening Interventions on Masonry Buildings." In 2008 SEISMIC ENGINEERING CONFERENCE: Commemorating the 1908 Messina and Reggio Calabria Earthquake. AIP, 2008. http://dx.doi.org/10.1063/1.2963929.
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Minowa, Chikahiro, Izumi Nakamura, and Osamu Furuya. "First Large Scale Shaking Table." In ASME 2022 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/pvp2022-84472.
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Abstract The large-scale shaking table in Tsukuba owned by National Research Center for Disaster Prevention, which was completed in 1970 after the 1964 Niigata Earthquake, will be closed in 2022. The table has an area of 15m × 15m and a exciting force of 360tons. The table was called as first large-scale shaking table. In 1970, the table was completed as one direction shaking table horizontal or vertical switching with stroke 60mm. In every year, several experiments were conducted. In 1988, the shaking table performance was improved. After Kobe Earthquake Damage, many shaking tables of high performance have been constructed. And it became clear that the seismic records exceeded 10m and 3m/s. Considering this situation, it must be said that the performance of the Tsukuba shaking table, which has been 50 years since its completion, has become difficult to meet the demands of the times. In this paper, it will be described the process of determining the construction specifications for the Tsukuba Shaking Table and the results of the main experiments conducted over 50 years, and this is the final word.
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Park, Dawon, Youngjun Choi, Heung Woon Jang, and Jung-Wuk Hong. "Seismic assessment of cracked masonry structures by shaking table tests." In Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems, edited by Daniele Zonta, Haiying Huang, and Zhongqing Su. SPIE, 2021. http://dx.doi.org/10.1117/12.2582930.
Full textReports on the topic "Seismic Shaking"
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Nema, Arpit, and Jose Restrep. Low Seismic Damage Columns for Accelerated Bridge Construction. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, December 2020. http://dx.doi.org/10.55461/zisp3722.
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This report describes the design, construction, and shaking table response and computation simulation of a Low Seismic-Damage Bridge Bent built using Accelerated Bridge Construction methods. The proposed bent combines precast post-tensioned columns with precast foundation and bent cap to simplify off- and on-site construction burdens and minimize earthquake-induced damage and associated repair costs. Each column consists of reinforced concrete cast inside a cylindrical steel shell, which acts as the formwork, and the confining and shear reinforcement. The column steel shell is engineered to facilitate the formation of a rocking interface for concentrating the deformation demands in the columns, thereby reducing earthquake-induced damage. The precast foundation and bent cap have corrugated-metal-duct lined sockets, where the columns will be placed and grouted on-site to form the column–beam joints. Large inelastic deformation demands in the structure are concentrated at the column–beam interfaces, which are designed to accommodate these demands with minimal structural damage. Longitudinal post-tensioned high-strength steel threaded bars, designed to respond elastically, ensure re-centering behavior. Internal mild steel reinforcing bars, debonded from the concrete at the interfaces, provide energy dissipation and impact mitigation.
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Gunay, Selim, Fan Hu, Khalid Mosalam, Arpit Nema, Jose Restrepo, Adam Zsarnoczay, and Jack Baker. Blind Prediction of Shaking Table Tests of a New Bridge Bent Design. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/svks9397.
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Considering the importance of the transportation network and bridge structures, the associated seismic design philosophy is shifting from the basic collapse prevention objective to maintaining functionality on the community scale in the aftermath of moderate to strong earthquakes (i.e., resiliency). In addition to performance, the associated construction philosophy is also being modernized, with the utilization of accelerated bridge construction (ABC) techniques to reduce impacts of construction work on traffic, society, economy, and on-site safety during construction. Recent years have seen several developments towards the design of low-damage bridges and ABC. According to the results of conducted tests, these systems have significant potential to achieve the intended community resiliency objectives. Taking advantage of such potential in the standard design and analysis processes requires proper modeling that adequately characterizes the behavior and response of these bridge systems. To evaluate the current practices and abilities of the structural engineering community to model this type of resiliency-oriented bridges, the Pacific Earthquake Engineering Research Center (PEER) organized a blind prediction contest of a two-column bridge bent consisting of columns with enhanced response characteristics achieved by a well-balanced contribution of self-centering, rocking, and energy dissipation. The parameters of this blind prediction competition are described in this report, and the predictions submitted by different teams are analyzed. In general, forces are predicted better than displacements. The post-tension bar forces and residual displacements are predicted with the best and least accuracy, respectively. Some of the predicted quantities are observed to have coefficient of variation (COV) values larger than 50%; however, in general, the scatter in the predictions amongst different teams is not significantly large. Applied ground motions (GM) in shaking table tests consisted of a series of naturally recorded earthquake acceleration signals, where GM1 is found to be the largest contributor to the displacement error for most of the teams, and GM7 is the largest contributor to the force (hence, the acceleration) error. The large contribution of GM1 to the displacement error is due to the elastic response in GM1 and the errors stemming from the incorrect estimation of the period and damping ratio. The contribution of GM7 to the force error is due to the errors in the estimation of the base-shear capacity. Several teams were able to predict forces and accelerations with only moderate bias. Displacements, however, were systematically underestimated by almost every team. This suggests that there is a general problem either in the assumptions made or the models used to simulate the response of this type of bridge bent with enhanced response characteristics. Predictions of the best-performing teams were consistently and substantially better than average in all response quantities. The engineering community would benefit from learning details of the approach of the best teams and the factors that caused the models of other teams to fail to produce similarly good results. Blind prediction contests provide: (1) very useful information regarding areas where current numerical models might be improved; and (2) quantitative data regarding the uncertainty of analytical models for use in performance-based earthquake engineering evaluations. Such blind prediction contests should be encouraged for other experimental research activities and are planned to be conducted annually by PEER.
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Hobbs, T. E., J. M. Journeay, A. S. Rao, L. Martins, P. LeSueur, M. Kolaj, M. Simionato, et al. Scientific basis of Canada's first public national seismic risk model. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330927.
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Natural Resources Canada, in partnership with the Global Earthquake Model Foundation, has prepared a public Canadian Seismic Risk Model to support disaster risk reduction efforts across industry and all levels of government, and to aid in Canada's adoption of the Sendai Framework for Disaster Risk Reduction. Developing this model has involved the creation of a national exposure inventory, Canadian specific fragility and vulnerability curves, and adjustment of the Canadian Seismic Hazard Model which forms the basis for the seismic provisions of the National Building Code of Canada. Using the Global Earthquake Model Foundation's OpenQuake Engine (OQ), risk modelling is completed using both deterministic and probabilistic risk calculations, under baseline and simulated retrofit conditions. Output results are available in all settled regions of Canada, at the scale of a neighbourhood or smaller. We report on expected shaking damage to buildings, financial losses, fatalities, and other impacts such as housing disruption and the generation of debris. This paper documents the technical details of the modelling approach including a description of novel datasets in use, as well as preliminary results for a magnitude 9.0 earthquake on the Cascadia megathrust and nation-wide 500 year expected probabilistic losses. These kinds of results, such as earthquake scenario impacts, loss exceedance curves, and annual average losses, provide a quantitative base of evidence for decision making at local, regional, and national levels.
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Wu, Yingjie, Selim Gunay, and Khalid Mosalam. Hybrid Simulations for the Seismic Evaluation of Resilient Highway Bridge Systems. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/ytgv8834.
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Bridges often serve as key links in local and national transportation networks. Bridge closures can result in severe costs, not only in the form of repair or replacement, but also in the form of economic losses related to medium- and long-term interruption of businesses and disruption to surrounding communities. In addition, continuous functionality of bridges is very important after any seismic event for emergency response and recovery purposes. Considering the importance of these structures, the associated structural design philosophy is shifting from collapse prevention to maintaining functionality in the aftermath of moderate to strong earthquakes, referred to as “resiliency” in earthquake engineering research. Moreover, the associated construction philosophy is being modernized with the utilization of accelerated bridge construction (ABC) techniques, which strive to reduce the impact of construction on traffic, society, economy and on-site safety. This report presents two bridge systems that target the aforementioned issues. A study that combined numerical and experimental research was undertaken to characterize the seismic performance of these bridge systems. The first part of the study focuses on the structural system-level response of highway bridges that incorporate a class of innovative connecting devices called the “V-connector,”, which can be used to connect two components in a structural system, e.g., the column and the bridge deck, or the column and its foundation. This device, designed by ACII, Inc., results in an isolation surface at the connection plane via a connector rod placed in a V-shaped tube that is embedded into the concrete. Energy dissipation is provided by friction between a special washer located around the V-shaped tube and a top plate. Because of the period elongation due to the isolation layer and the limited amount of force transferred by the relatively flexible connector rod, bridge columns are protected from experiencing damage, thus leading to improved seismic behavior. The V-connector system also facilitates the ABC by allowing on-site assembly of prefabricated structural parts including those of the V-connector. A single-column, two-span highway bridge located in Northern California was used for the proof-of-concept of the proposed V-connector protective system. The V-connector was designed to result in an elastic bridge response based on nonlinear dynamic analyses of the bridge model with the V-connector. Accordingly, a one-third scale V-connector was fabricated based on a set of selected design parameters. A quasi-static cyclic test was first conducted to characterize the force-displacement relationship of the V-connector, followed by a hybrid simulation (HS) test in the longitudinal direction of the bridge to verify the intended linear elastic response of the bridge system. In the HS test, all bridge components were analytically modeled except for the V-connector, which was simulated as the experimental substructure in a specially designed and constructed test setup. Linear elastic bridge response was confirmed according to the HS results. The response of the bridge with the V-connector was compared against that of the as-built bridge without the V-connector, which experienced significant column damage. These results justified the effectiveness of this innovative device. The second part of the study presents the HS test conducted on a one-third scale two-column bridge bent with self-centering columns (broadly defined as “resilient columns” in this study) to reduce (or ultimately eliminate) any residual drifts. The comparison of the HS test with a previously conducted shaking table test on an identical bridge bent is one of the highlights of this study. The concept of resiliency was incorporated in the design of the bridge bent columns characterized by a well-balanced combination of self-centering, rocking, and energy-dissipating mechanisms. This combination is expected to lead to minimum damage and low levels of residual drifts. The ABC is achieved by utilizing precast columns and end members (cap beam and foundation) through an innovative socket connection. In order to conduct the HS test, a new hybrid simulation system (HSS) was developed, utilizing commonly available software and hardware components in most structural laboratories including: a computational platform using Matlab/Simulink [MathWorks 2015], an interface hardware/software platform dSPACE [2017], and MTS controllers and data acquisition (DAQ) system for the utilized actuators and sensors. Proper operation of the HSS was verified using a trial run without the test specimen before the actual HS test. In the conducted HS test, the two-column bridge bent was simulated as the experimental substructure while modeling the horizontal and vertical inertia masses and corresponding mass proportional damping in the computer. The same ground motions from the shaking table test, consisting of one horizontal component and the vertical component, were applied as input excitations to the equations of motion in the HS. Good matching was obtained between the shaking table and the HS test results, demonstrating the appropriateness of the defined governing equations of motion and the employed damping model, in addition to the reliability of the developed HSS with minimum simulation errors. The small residual drifts and the minimum level of structural damage at large peak drift levels demonstrated the superior seismic response of the innovative design of the bridge bent with self-centering columns. The reliability of the developed HS approach motivated performing a follow-up HS study focusing on the transverse direction of the bridge, where the entire two-span bridge deck and its abutments represented the computational substructure, while the two-column bridge bent was the physical substructure. This investigation was effective in shedding light on the system-level performance of the entire bridge system that incorporated innovative bridge bent design beyond what can be achieved via shaking table tests, which are usually limited by large-scale bridge system testing capacities.
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Paul, C., and J. F. Cassidy. Seismic hazard investigations at select DND facilities in Southwestern British Columbia: subduction, in-slab, and crustal scenarios. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/331199.
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Southwest British Columbia has some of the highest seismic hazard in Canada and is home to facilities owned by the Department of National Defence which support operations on the west coast of Canada. The potential impact of seismic hazards on these government facilities are investigated here. The hazard is from three primary sources: subduction interface, crustal and in-slab earthquakes. NRCan, in consultation with DRDC have produced representative earthquake scenarios for each of these sources. The subduction scenario we constructed was an M8.9 earthquake extending along the entire Cascadia Subduction Zone from 4 to 18 km depth. We used an M6.8 earthquake occurring along a 30 km fault at between 52 and 60 km depth below Boundary Bay to represent in-slab events. The final scenario, representing a crustal source, was an M6.4 along the central 47 km of the Leech River Valley-Devil's Mountain Fault system. We found that the Cascadia subduction scenario dominated the shaking hazard over much of the study region. Meanwhile, the in-slab and crustal scenarios have higher but more localized hazards in Vancouver and Victoria. In addition to the primary ground motion hazard, we also examined secondary seismic hazards: secondary amplification effects, landslides, liquefaction, surface ruptures, tsunami, flooding, fire, and aftershocks. Each of the secondary hazards had varying impacts depending on the scenario and locations within the region.
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Welch, David, and Gregory Deierlein. Technical Background Report for Structural Analysis and Performance Assessment (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/yyqh3072.
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This report outlines the development of earthquake damage functions and comparative loss metrics for single-family wood-frame buildings with and without seismic retrofit of vulnerable cripple wall and stem wall conditions. The underlying goal of the study is to quantify the benefits of the seismic retrofit in terms of reduced earthquake damage and repair or reconstruction costs. The earthquake damage and economic losses are evaluated based on the FEMA P-58 methodology, which incorporates detailed building information and analyses to characterize the seismic hazard, structural response, earthquake damage, and repair/reconstruction costs. The analyses are informed by and include information from other working groups of the Project to: (1) summarize past research on performance of wood-frame houses; (2) identify construction features to characterize alternative variants of wood-frame houses; (3) characterize earthquake hazard and ground motions in California; (4) conduct laboratory tests of cripple wall panels, wood-frame wall subassemblies and sill anchorages; and (5) validate the component loss models with data from insurance claims adjustors. Damage functions are developed for a set of wood-frame building variants that are distinguished by the number of stories (one- versus two-story), era (age) of construction, interior wall and ceiling materials, exterior cladding material, and height of the cripple walls. The variant houses are evaluated using seismic hazard information and ground motions for several California locations, which were chosen to represent the range seismicity conditions and retrofit design classifications outlined in the FEMA P-1100 guidelines for seismic retrofit. The resulting loss models for the Index Building variants are expressed in terms of three outputs: Mean Loss Curves (damage functions), relating expected loss (repair cost) to ground-motion shaking intensity, Expected Annual Loss, describing the expected (mean) loss at a specific building location due to the risk of earthquake damage, calculated on an annualized basis, and Expected RC250 Loss, which is the cost of repairing damage due to earthquake ground shaking with a return period of 250 years (20% chance of exceedance in 50 years). The loss curves demonstrate the effect of seismic retrofit by comparing losses in the existing (unretrofitted) and retrofitted condition across a range of seismic intensities. The general findings and observations demonstrate: (1) cripple walls in houses with exterior wood siding are more vulnerable than ones with stucco siding to collapse and damage; (2) older pre-1945 houses with plaster on wood lath interior walls are more susceptible to damage and losses than more recent houses with gypsum wallboard interiors; (3) two-story houses are more vulnerable than one-story houses; (4) taller (e.g., 6-ft-tall) cripple walls are generally less vulnerable to damage and collapse than shorter (e.g., 2-ft-tall) cripple walls; (5) houses with deficient stem wall connections are generally observed to be less vulnerable to earthquake damage than equivalent unretrofitted cripple walls with the same superstructure; and (6) the overall risk of losses and the benefits of cripple wall retrofit are larger for sites with higher seismicity. As summarized in the report, seismic retrofit of unbraced cripple walls can significantly reduce the risk of earthquake damage and repair costs, with reductions in Expected RC250 Loss risk of up to 50% of the house replacement value for an older house with wood-frame siding at locations of high seismicity. In addition to the reduction in repair cost risk, the seismic retrofit has an important additional benefit to reduce the risk of major damage that can displace residents from their house for many months.
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Plourde, A. P., and J. F. Cassidy. Mapping tectonic stress at subduction zones with earthquake focal mechanisms: application to Cascadia, Japan, Nankai, Mexico, and northern Chile. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330943.
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Earthquake focal mechanisms have contributed substantially to our understanding of modern tectonic stress regimes, perhaps more than any other data source. Studies generally group focal mechanisms by epicentral location to examine variations in stress across a region. However, stress variations with depth have rarely been considered, either due to data limitations or because they were believed to be negligible. This study presents 3D grids of tectonic stress tensors using existing focal mechanism catalogs from several subduction zones, including Cascadia, Japan, Nankai, Mexico, and northern Chile. We bin data into 50 x 50 x 10 km cells (north, east, vertical), with 50% overlap in all three directions. This resulted in 181380 stress inversions, with 90% of these in Japan (including Nankai). To the best of our knowledge, this is the first examination of stress changes with depth in several of these regions. The resulting maps and cross-sections of stress can help distinguish locked and creeping segments of the plate interface. Similarly, by dividing the focal mechanism catalog in northern Japan into those before and those &gt;6 months after the 2011 Mw 9.1 Tohoku-Oki earthquake, we are able to produce detailed 3D maps of stress rotation, which is close to 90° near the areas of highest slip. These results could inform geodynamic rupture models of future megathrust earthquakes in order to more accurately estimate slip, shaking, and seismic hazard. Southern Cascadia and Nankai appear to have sharp stress discontinuities at ~20 km depth, and northern Cascadia may have a similar discontinuity at ~30 km depth. These stress boundaries may relate to rheological discontinuities in the forearc, and may help us unravel how forearc composition influences subduction zone behaviour and seismic hazard.
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Steudlein, Armin, Besrat Alemu, T. Matthew Evans, Steven Kramer, Jonathan Stewart, Kristin Ulmer, and Katerina Ziotopoulou. PEER Workshop on Liquefaction Susceptibility. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, May 2023. http://dx.doi.org/10.55461/bpsk6314.
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Seismic ground failure potential from liquefaction is generally undertaken in three steps. First, a susceptibility evaluation determines if the soil in a particular layer is in a condition where liquefaction triggering could potentially occur. This is followed by a triggering evaluation to estimate the likelihood of triggering given anticipated seismic demands, environmental conditions pertaining to the soil layer (e.g., its depth relative to the ground water table), and the soil state. For soils where triggering can be anticipated, the final step involves assessments of the potential for ground failure and its impact on infrastructure systems. This workshop was dedicated to the first of these steps, which often plays a critical role in delineating risk for soil deposits with high fines contents and clay-silt-sand mixtures of negligible to moderate plasticity. The workshop was hosted at Oregon State University on September 8-9, 2022 and was attended by 49 participants from the research, practice, and regulatory communities. Through pre-workshop polls, extended abstracts, workshop presentations, and workshop breakout discussions, it was demonstrated that leaders in the liquefaction community do not share a common understanding of the term “susceptibility” as applied to liquefaction problems. The primary distinction between alternate views concerns whether environmental conditions and soil state provide relevant information for a susceptibility evaluation, or if susceptibility is a material characteristic. For example, a clean, dry, dense sand in a region of low seismicity is very unlikely to experience triggering of liquefaction and would be considered not susceptible by adherents of a definition that considers environmental conditions and state. The alternative, and recommended, definition focusing on material susceptibility would consider the material as susceptible and would defer consideration of saturation, state, and loading effects to a separate triggering analysis. This material susceptibility definition has the advantage of maintaining a high degree of independence between the parameters considered in the susceptibility and triggering phases of the ground failure analysis. There exist differences between current methods for assessing material susceptibility – the databases include varying amount of test data, the materials considered are distinct (from different regions) and have been tested using different procedures, and the models can be interpreted as providingdifferent outcomes in some cases. The workshop reached a clear consensus that new procedures are needed that are developed using a new research approach. The recommended approach involves assembling a database of information from sites for which in situ test data are available (borings with samples, CPTs), cyclic test data are available from high-quality specimens, and a range of index tests are available for important layers. It is not necessary that the sites have experienced earthquake shaking for which field performance is known, although such information is of interest where available. A considerable amount of data of this type are available from prior research studies and detailed geotechnical investigations for project sites by leading geotechnical consultants. Once assembled and made available, this data would allow for the development of models to predict the probability of material susceptibility given various independent variables (e.g., in-situ tests indices, laboratory index parameters) and the epistemic uncertainty of the predictions. Such studies should be conducted in an open, transparent manner utilizing a shared database, which is a hallmark of the Next Generation Liquefaction (NGL) project.
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SHAKING TABLE TEST OF NEW LIGHT STEEL STRUCTURE SYSTEM. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.342.
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The low-rise cold-formed thin-walled steel buildings have good seismic performance, and their lateral force resistance is generally provided by the pull-out parts, the wall skeleton support system, and the skin effect between the wall skeleton and the wall. However, the current cold-formed thin-walled steel residential system is difficult to meet the seismic requirements of multi-storey cold-formed thin-walled steel buildings in high intensity areas. In this paper, the thin steel brace and light steel skeleton are combined to form a wall skeleton with a new support system with "truss structure" at the top and bottom of the skeleton. A full-scale shaking table test model is designed and made, and its structural dynamic characteristics and dynamic response are studied by shaking table test. The results show that the horizontal steel strap and inclined steel strap are used to form a "flat" structure with steel columns and guide beams, and the triangular element on the "flat" structure is used to restrict the displacement of the local area at the top and bottom of the wall skeleton and improve the stiffness of the area. T1 model performs better than T2 model, and has better seismic application potential for developing multi-storey cold-formed thin-walled steel residential buildings, which can meet the engineering needs.
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Map showing predicted seismic-shaking intensities of an earthquake in San Mateo County, California, comparable in magnitude to the 1906 San Francisco earthquake. US Geological Survey, 1986. http://dx.doi.org/10.3133/i1257h.
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