Dissertations / Theses on the topic 'CYCLIC PILE LOAD'
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1
Runnels, Immanuel Kaleoonalani. "Dynamic Full-Scale Testing of a Pile Cap with Loose Silty Sand Backfill." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1854.pdf.
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Sutman, Melis. "Thermo-Mechanical Behavior of Energy Piles: Full-Scale Field Testing and Numerical Modeling." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/82438.
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Energy piles are deep foundation elements designed to utilize near-surface geothermal
energy, while at the same time serve as foundations for buildings. The use of energy piles for
geothermal heat exchange has been steadily increasing during the last decade, yet there are
still pending questions on their thermo-mechanical behavior. The change in temperature
along energy piles, resulting from their employment in heat exchange operations, causes axial
displacements, thermally induced axial stresses and changes in mobilized shaft resistance
which may have possible effects on their behavior. In order to investigate these effects, an
extensive field test program, including conventional pile load tests and application of
heating-cooling cycles was conducted on three energy piles during a period of six weeks.
Temperature changes were applied to the test piles with and without maintained mechanical
loads to investigate the effects of structural loads on energy piles. Moreover, the lengths of
the test piles were determined to represent different end-restraining conditions at the toe.
Various sensors were installed to monitor the strain and temperature changes along the test
piles. Axial stress and shaft resistance profiles inferred from the field test data along with the
driven conclusions are presented herein for all three test piles. It is inferred from the field test
results that changes in temperature results in thermally induced compressive or tensile axial
stresses along energy piles, the magnitude of which increases with higher restrictions such as
structural load on top or higher toe resistance. Moreover, lower change in shaft resistance is
observed with increasing restrictions along the energy piles. In addition to the design,
deployment, and execution of the field test, a thermo-mechanical cyclic numerical model was
developed as a part of this research. In this numerical model, load-transfer approach was
coupled with the Masing's Rule in order to simulate the two-way cyclic axial displacement of
energy piles during temperature changes. The numerical model was validated using the field
test results for cyclic thermal load and thermo-mechanical load applications. It is concluded
that the use of load-transfer approach coupled with the Masing's Rule is capable of
simulating the cyclic thermo-mechanical behavior of energy piles.Ph. D.
3
Cummins, Colin Reuben. "Behavior of a Full-Scale Pile Cap with Loosely and Densely Compacted Clean Sand Backfill under Cyclic and Dynamic Loadings." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/1684.
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A series of lateral load tests were performed on a full-scale pile cap with three different backfill conditions, namely: with no backfill present, with densely compacted clean sand in place, and with loosely compacted clean sand in place. In addition to being displaced under a static loading, the pile cap was subjected to low frequency, small displacement loading cycles from load actuators and higher frequency, small displacement, dynamic loading cycles from an eccentric mass shaker. The passive earth pressure from the backfill was found to significantly increase the load capacity of the pile cap. At a displacement of about 46 mm, the loosely and densely compacted backfills increased the total resistance of the pile cap otherwise without backfill by 50% and 245%, respectively. The maximum passive earth pressure for the densely compacted backfill occurred at a displacement of approximately 50 mm, which corresponds to a displacement to pile cap height ratio of 0.03. Contrastingly passive earth pressure for the loosely compacted backfill occurred at a displacement of approximately 40 mm. Under low and high frequency cyclic loadings, the stiffness of the pile cap system increased with the presence of the backfill material. The loosely compacted backfill generally provided double the stiffness of the no backfill case. The densely compacted backfill generally provided double the stiffness of the loosely compacted sand, thus quadrupling the stiffness of the pile cap relative to the case with no backfill present. Under low frequency cyclic loadings, the damping ratio of the pile cap system decreased with cap displacement and with increasing stiffness of backfill material. After about 20 mm of pile cap displacement, the average damping ratio was about 18% with the looser backfill and about 24% for the denser backfill. Under higher frequency cyclic loadings, the damping ratio of the pile cap system was quite variable and appeared to vary with frequency. Damping ratios appear to peak in the vicinity of the natural frequency of the pile cap system for each backfill condition. On the whole, damping ratios tend to range between 10 and 30%, with an average of about 20% for the range of frequencies and displacement amplitudes occurring during the tests. The similar amount of damping for different ranges of frequency suggests that dynamic loadings do not appreciably increase the apparent resistance of the pile cap relative to slowly applied cyclic loadings.
4
Pruett, Joshua M. "Performance of a Full-Scale Lateral Foundation with Fine and Coarse Gravel Backfills Subjected to Static, Cyclic, and Dynamic Lateral Loads." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/2317.
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Full-scale lateral load tests were performed on a pile cap with five backfill conditions: no backfill, densely compacted fine gravel, loosely compacted fine gravel, densely compacted coarse gravel, and loosely compacted coarse gravel. Static loads, applied by hydraulic load actuators, were followed by low-frequency, actuator-driven cyclic loads as well as higher frequency dynamic loads from an eccentric mass shaker. Passive resistance from the backfill significantly increased the lateral capacity of the pile cap. Densely compacted backfill materials contributed about 70% of the total system resistance, whereas loosely compacted backfill materials contributed about 40%. The mobilized passive resistance occurred at displacement-to-height ratios of about 0.04 for the densely compacted gravels, whereas passive resistance in the loosely compacted materials does not fully mobilize until greater displacements are reached. Three methods were used to model the passive resistance of the backfill. Comparisons between calculated and measured responses for the densely compacted backfills indicate that in-situ shear strength test parameters provide reasonable agreement when a log-spiral method is used. Reasonable agreement for the loosely compacted backfills was obtained by either significantly reducing the interface friction angle to near zero or reducing the soil's frictional strength by a factor ranging from 0.65 to 0.85. Cracking, elevation changes, and horizontal strains in the backfill indicate that the looser materials fail differently than their densely compacted counterparts. Under both low frequency cyclic loading and higher frequency shaker loading, the backfill significantly increased the stiffness of the system. Loosely compacted soils approximately doubled the stiffness of the pile cap without backfill and densely compacted materials roughly quadrupled the stiffness of the pile cap. The backfill also affected the damping of the system in both the cyclic and the dynamic cases, with a typical damping ratio of at least 15% being observed for the foundation system.
5
Abood, Awad Shihan. "Load capacity of piled foundations under non-cyclic and cyclic uplift loading." Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329618.
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Dubdub, Ahmad Jassim. "Load capacity of piled foundations under non-cyclic and cyclic compressive loading." Thesis, Cardiff University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309371.
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7
Li, Zheming. "Piled foundations subjected to cyclic loads or earthquakes." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609107.
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8
Chiluwal, Sundar. "Numerical Modeling of Helical Pile-to-Foundation Connections subjected to Monotonic and Cyclic Loads." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1576021464589307.
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9
Saldivar-Moguel, Emilio Enrique. "Investigation into the behaviour of displacement piles under cyclic and seismic loads." Thesis, Imperial College London, 2002. http://hdl.handle.net/10044/1/7589.
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10
Reddy, Eadala Sai Baba. "An investigation into the behaviour of piles in sand under vertical cyclic tensile loads." Thesis, University of Nottingham, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.339687.
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11
Pasten, Cesar. "Geomaterials subjected to repetitive loading: implications on energy systems." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47740.
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Improvements in quality of life, population growth, and environmental restrictions associated with the burning of fossil fuels will accentuate the need for renewable energy and energy geo-storage. A salient characteristic of these systems is that they impose numerous cycles of effective stress, temperature, and humidity on the surrounding geomaterials. This thesis quantifies future energy consumption based on realizable scenarios and explores the behavior of geomaterials subjected to mechanical and thermal cycles in view of energy-related applications. The long-term behavior of geotechnical systems subjected to a large number of mechanical load cycles is studied with a new numerical scheme based on a hybrid finite element formulation. The numerical scheme satisfies initial conditions as well as fundamental characteristics of soil behavior, such as threshold strain, terminal density, and long-term ratcheting. Numerical results show that shallow foundations subjected to repetitive loading experience strain accumulation and stress redistribution. On the other hand, the long-term behavior of energy piles, exposed geomembranes on slopes, and jointed rock masses subjected to cyclic thermal changes is studied using a combination of numerical, analytical, and experimental methods. Results show that thermal cycles lead to the gradual accumulation of plastic displacements, which may be amplified by thermally-induced wedging in jointed rock masses. In general, cumulative effects caused by repetitive loads increase with the number of cycles, the static factor of safety, the amplitude of the cyclic excitation, and the magnitude of the cyclically-induced displacement with respect to the critical elastic displacement.
12
Arora, Divyesh. "Hybridation directe d’une pile à combustible PEM et d’un organe supercapacitif de stockage : étude comparative du vieillissement en cyclage urbain, et gestion optimale de la consommation d’hydrogène." Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0097.
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La pile à combustible (FC) est peu adaptée aux variations brusques de puissance rencontrées dans les applications transport. L’hybridation de la pile à un supercondensateur (SC) a alors été étudiée, puisque cet organe de stockage capacitif permet de gérer les transitoires de puissance. L’hybridation est directe/passive, permettant ainsi de réduire le volume, la masse et le coût du système. Initialement, la faisabilité et l’impact de la taille du SC sur la performance de la FC en mono-cellule ont été examinés numériquement. Cette modélisation montre que l’augmentation de la taille du SC renforce l’effet de lissage induit par l’utilisation du SC sur le courant de la FC. Il en résulte des variations lentes et une réduction des amplitudes de courant et de tension, une diminution du courant efficace de la FC, et donc des pertes électriques de celle-ci. L’hybridation de la FC, comparativement à son fonctionnement seule, permet en outre de réduire la surconsommation en H2 de près de 50 % dans les mêmes conditions opératoires. Ces résultats ont été validés par des essais expérimentaux réalisés en mono-cellule et 3-cellules de 100 cm2 hybridée ou non. Par la suite, toujours en utilisant le protocole de cyclage urbain (FC-DLC), la durabilité de la FC a été étudiée lors d’essais de longue durée. La durabilité de la FC, qu’elle soit hybridée ou non, est la même. L’hybridation n’améliore donc pas la durée de vie de la FC mais ne lui nuit pas non plus. Par la suite, afin d’encore réduire la surconsommation en H2 en longue durée cyclage, différentes stratégies ont été étudiées : diminution du débit minimum des gaz imposé par le cyclage et diminution du coefficient de surstœchiométrie en H2. Ces changements n’ont pas d’influence sur la durabilité de la pile hybridée et ont permis de réduire à 10 % la surconsommation en hydrogène. La FC non hybridée, quant à elle, a vu sa durabilité divisée par deux lors de la diminution des débits minimum et ne fonctionnait pas avec le coefficient de surstœchiométrie ramené à 1,1. Ensuite, les travaux ont été étendus à un stack FC de forte puissance (Système Ballard de 1,2 kW) hybridé à deux modules de SC de 165 F (Maxwell Technologies). En final, un système hybride de 34 kW (FC de 10 kW et SC de 566.67 F) a montré des performances suffisantes pour une application transport urbain et péri-urbain. De plus, comparativement à une pile de 34 kW 21 % d’hydrogène sont économisés et l'investissement des équipements peut être réduit de près 50 %The fuel cell (FC) is poorly adapted to the sudden variations in power encountered in transport applications. The FC hybridization to a supercapacitor (SC) was then studied, since this capacitive storage device allows to manage the power transients. Hybridization is direct/passive, thus reducing the volume, mass and cost of the system. Initially, the feasibility and the impact of SC size on FC performance have been examined numerically. Theoretical investigations show that increasing the size of SC enhances the smoothing effect introduced by the supercapacitor on FC current. This results into slow variations and reduction in both current and voltage amplitudes, a decrease in the fuel cell’s effective current, and therefore in FC electrical losses. Hybridization, compared to its FC operation alone, still reduces hydrogen overconsumption by nearly 50 % under the same operating conditions. These results have been validated by experimental tests carried out on a 100 cm2 single FC and a 3 cell stack. Later, the durability of the FC system has been investigated through long term tests. These durability tests have been conducted on the 100 cm2 single FC test bench using urban cycling protocol (FC-DLC), for both hybridized and unhybridized FC system, with continuous evaluation of degradation extent and causes. These tests suggest no detrimental impact on durability of the FC. For these two operating modes, a progressive aging of the gas diffusion layer seems to appear. Subsequently, in order to further reduce the overconsumption of hydrogen in long-term FC-DLC cycling, different strategies were studied: reducing the minimum gas flow rate imposed by FC-DLC cycling from 0.2 to 0.05 A cm-2, and reducing the hydrogen overstoichiometry coefficient from 1.2 to 1.1. These changes have no influence on the durability of the hybrid cell and have reduced hydrogen overconsumption to 10 %. On the contrary, in case of the unhybridized FC, durability was halved as minimum flows were reduced and it did not work when the overstoichiometry reduced coefficient. Further, work has been extended to high power FC systems (1.2 kW FC system, hybridized with two modules of 165 F, SC module). Finally, the FC downsizing has been demonstrated from 34kW FC system to hybrid source system of 10kW FC hybridized with 566.64 F SC, presenting 21 % hydrogen saving and nearly 50 % net cost savings
13
ITOH, Yoshito, Naohiko WATANABE, Yasuo KITANE, Kazuo FURUNISHI, 義人 伊藤, 尚彦 渡邊, 安雄 北根, and 和夫 古西. "添接板補修された断面欠損鋼管の繰返し曲げ挙動に関する研究." 日本鋼構造協会, 2011. http://hdl.handle.net/2237/18853.
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IQUBAL, Md KHALID. "CYCLIC PILE LOAD TEST ON MODEL PILES IN SAND." Thesis, 2012. http://dspace.dtu.ac.in:8080/jspui/handle/repository/13914.
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M.TECHPiles are vertical or slightly slanting structural foundation members, having relatively small cross-sectional dimensions With respect to their length. They are introduced into the soil and transmit the loads and forces acting on the superstructure to the subsoil. The length, method of installation, and way of acting of piles can vary greatly, and thus they are easily adaptable to various conditions and requirements. Conducting a load test on a pile to determine its ultimate or safe load carrying capacity is indeed a costly and time-consuming enterprise. However, as stated earlier, it is the most reliable means of determining the load carrying Capacity of a pile, since, as a deep foundation; a pile passes through a number of different layers of soil with varying sometimes uncertain properties. Hence, in spite of the cost, time and effort, one may have to resort to a load test in many instances where one may be doubtful whether calculation by static or dynamic formulae would be sufficiently reliable. In fact, in most piling jobs, it is usual to stipulate that load test should be conducted on one pile, if not more. The load test on pile involves measuring deflection against loads applied in stages till the soil fails under the load. The data is plotted as a cyclic load settlement curve from which the ultimate load carrying capacity is interpreted. When a pile is loaded by an axial load at ground level, initially the applied load is distributed as friction load within a certain length of the pile measured from its top. When the pile is loaded first the load is taken by surface of pile in entire length. This is due to friction of surface this is called skin friction. After that the load of superstructure is taken by the base of pile in case of cohesionless soil. This resistance of pile is known as tip resistance. It is only after the full length of the pile develops frictional resistance at a certain stage of loading, that a part of the load is transferred to the soil at the base as point load. With the increase in load at the top after this stage, both the frictional as well as point loads increase. The frictional load attains a maximum value at a certain load level and will not further increase upon increase in axial load. But the point load still keeps on increasing till the soil at the base fails in local shear. The total settlement S of a pile obtained from a pile load test comprises of two components, namely, elastic settlement, Se and plastic settlement Sp. Piles are vertical or slightly slanting structural foundation members, having relatively small cross-sectional dimensions With respect to their length. They are introduced into the soil and transmit the loads and forces acting on the superstructure to the subsoil. The length, method of installation, and way of acting of piles can vary greatly, and thus they are easily adaptable to various conditions and requirements. Conducting a load test on a pile to determine its ultimate or safe load carrying capacity is indeed a costly and time-consuming enterprise. However, as stated earlier, it is the most reliable means of determining the load carrying Capacity of a pile, since, as a deep foundation; a pile passes through a number of different layers of soil with varying sometimes uncertain properties. Hence, in spite of the cost, time and effort, one may have to resort to a load test in many instances where one may be doubtful whether calculation by static or dynamic formulae would be sufficiently reliable. In fact, in most piling jobs, it is usual to stipulate that load test should be conducted on one pile, if not more. The load test on pile involves measuring deflection against loads applied in stages till the soil fails under the load. The data is plotted as a cyclic load settlement curve from which the ultimate load carrying capacity is interpreted. When a pile is loaded by an axial load at ground level, initially the applied load is distributed as friction load within a certain length of the pile measured from its top. When the pile is loaded first the load is taken by surface of pile in entire length. This is due to friction of surface this is called skin friction. After that the load of superstructure is taken by the base of pile in case of cohesionless soil. This resistance of pile is known as tip resistance. It is only after the full length of the pile develops frictional resistance at a certain stage of loading, that a part of the load is transferred to the soil at the base as point load. With the increase in load at the top after this stage, both the frictional as well as point loads increase. The frictional load attains a maximum value at a certain load level and will not further increase upon increase in axial load. But the point load still keeps on increasing till the soil at the base fails in local shear. The total settlement S of a pile obtained from a pile load test comprises of two components, namely, elastic settlement, Se and plastic settlement Sp.
15
Lai, Chia-Hung, and 賴佳宏. "Analysis of Cyclic Load Pile Test Results." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/80080037631892084148.
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CHEN, JHENG-HONG, and 陳政宏. "Study of Single Pile Behavior in Submerged Sands under Cyclic Lateral Load." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/94667512701672842453.
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碩士逢甲大學
土木工程所
99
In this project, as the main is to research indoor model pile. The project using 19mm, 25mm, 32mm, 38mm, 48mm, five kinds of different outside length square hollow pile; 22.15m, 29.29mm, 37.63mm, 44.78mm, 56.7mm, five kinds of different outer diameter circular hollow pile to test indoor model pile withstand lateral cyclic loading in varies combinations, in order to probe into the comparison of model pile behavior in submerged sand. The results reveal that under the same cycles, all the bending moment of square hollow pile are larger than the bending moment of circular hollow pile. The comparison of response curve in the same moment of inertia, square hollow pile is more preferable to circular hollow pile, estimation only under the terms that circular hollow pile must be greater than the value of a size or moment of inertia, the design will be more preferable to square hollow pile. The soil will get tighter and tighter when the cycles of lateral cyclic loading increased, the more the cycles are, the situation along the pile general withstand higher soil reaction, the maximum bending moment on pile shaft occur in the pile at the distance 10 times to 15 times the pile outside length near the pile head, when pile withstand lateral force the bending moment value varies more when the frequency of cycle increased; reveal the square hollow pile is able to withstand large soil reaction and lateral force than circular hollow pile.And when changing the size of square hollow pile or circular hollow pile, the large the size of pile is, the soil reaction and lateral force are.
17
Tzeng, Yung-Cheng, and 曾永成. "Behavior of Model Pile in Saturated Sand Subjected to Cyclic Lateral Load." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/19203214806559243333.
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碩士國立臺灣大學
土木工程學研究所
97
In order to understand the behavior of soil-pile interaction for a pile foundation subjected to lateral loading, a series of lateral load tests were conducted on the instrumented model pile with a length of 1.50 m﹐an outer diameter of 101.6 mm and a wall thickness of 3 mm within a saturated Vietnam sand specimen inside the laminar shear box at National Center for Research on Earthquake Engineering (NCREE). The lateral load tests on the model pile with and without sand were performed under static and cyclic loading conditions. The input motions of cyclic loading included sinusoidal waves with amplitudes ranging from 1 mm to 5 mm and frequencies of 0.5 Hz﹐1 Hz and 2 Hz. The dial gages, strain gages and piezometers were installed at various locations to measure the responses of pile and soil under different loading conditions. The moment-curvature relation of model pile without sand specimen presented a linear-elastic behavior in the lateral load test. The stiffness of pile top displacement of model pile in the sand specimen decreases with increase of deflection at pile top and increases with frequency. The damping ratios of the model pile within the sand specimen in lateral load test increase with increase of deflection and decrease with frequency. The p-y curves were obtained based on the measured pile curvatures along the pile. The modulus of p-y curve increases with the depth of the pile﹐and the modulus of p-y curve at the same depth of the pile increases with loading frequency. It was observed that the generated excess pore water pressure mainly occurred near the pile perimeter when the model pile subjected to lateral load. The positive excess pore water pressures were generated on the compression side of pile, while on the extension side, the negative excess pore water pressures were occurred.
18
Oghabi, PEGAH. "EXPERIMENTAL RESPONSE OF A PILE IN SAND UNDER STATIC AND CYCLIC LATERAL LOADS." Thesis, 2014. http://hdl.handle.net/1974/12173.
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Piles are engineering structures which are subjected to axial and lateral loading. In this dissertation, pile load tests were performed on a full-scale fabricated pile to understand lateral pile responses under static and cyclic loading. The experiments were performed on a fabricated test pile at the Geo-Engineering Laboratory at Queen's University. Dry loose Olimag Synthetic Olivine sand was used as the test soil.
Instrumentation including axial strain gauges, null sensors (earth pressure sensors) and string potentiometers were used to monitor pile responses throughout the tests. What differentiates the current study from previous investigations is direct measurements of lateral earth pressure on a test pile using those null sensors with conventional measurements of curvature and deformation. The null sensors of Talesnick (2005) have ‘infinite stiffness’ and calibration that is almost independent of the soil type, soil condition and stress history, qualities that make the sensor superior to other commercially available sensors.
The initial pile response under static loading was examined. Previous laterally loaded pile test programs have utilized curvature measurements to infer moments, and differentiation of moments to determine lateral forces. Comparisons with the directly measured pressures confirmed the effectiveness of differentiated moments. To understand offshore structures, the behaviour of a pile subjected to cyclic loading is examined and explained by elastic soil response at low load levels and the progressive development of inelastic response at higher load levels. In addition, the loading condition (i.e. two-way versus one-way loading) was found to have a substantial effect on pile responses. The pressure distributions for two-way cyclic loading suggest that the lateral pressure is proportional to displacement with peak pressures near the ground surface during elastic responses. The peak lateral pressures move deeper towards the point of rotation with increasing cyclic loads to generate inelastic responses. However, the lateral pressure response is consistently inelastic for one-way loading.Thesis (Master, Civil Engineering) -- Queen's University, 2014-05-02 20:29:56.489
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Hui, Yu-Wen, and 游文輝. "Investigatio of behavior of caisson-type pile foundation subjected cyclic lateral load in sand." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/04987621327209675914.
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碩士國立中央大學
土木工程研究所
90
When free way is constructed in the mountain area, the foundation of bridge will be inevitably erected in the slope and one of most frequently used foundation is the caisson-type pile foundation. In addition to supporting the gravity load transmitted from the bridge structure, the caisson-type pile foundation will be subjected to lateral load induced by wind, earthquake and so on. Therefore, it is important that the behavior of caisson-type foundation under the action of lateral load be investigated. In this study, the behavior of caisson-type pile foundation subjected cyclic lateral load is investigated using the geotechnical centrifuge. The distribution of bending moment along the shaft of caisson-type pile is obtain by using the modified polynomial approach and the measured values, which can then be used to find the soil reaction by differentiating twice and the deflection by integrating twice. The results show that the purposed test procedure has a very good repeatability. As the number of cycles increases, the increment of bending moment decreases and the lateral load will approach a constant value, while the pile-head displacement increases. For caisson-type pile embedded in a low-density sandy soil stratum, the decrease in moment will be smaller and the residual moment will be larger, as compared with that embedded in high-density sandy soil stratum.
20
Tan, Wen Jui, and 譚文瑞. "Lateral Response Analysis of Pile to Cyclic Load in Homogenious and Non-hpmogenious Subgrade." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/94832364011965741883.
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Wu, Chun-cheng, and 伍中政. "A Study on the behavior of model spliced pile in sand under cyclic lateral load." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/85467789693723778295.
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碩士逢甲大學
土木工程所
94
In pile foundation engineering, pile foundations are extended to stiff soil or rock mass by splicing piles to meet the designed demand of foundation bearing. In addition to the loading from the axial direction, the lateral horizontal force may create an internal stress vertical to the pile axis and cause impacts on the pile foundation. This research used a 90cm long model spliced pile welded with two 45cm full-length model piles to investigate the mechanical behavior caused by lateral forces on single and group spliced piles and compare the differences with non-spliced full-length model piles. In this experiment, an indoor simulation test of cyclic lateral loading on pile foundations was conducted. According to the test results, the following conclusions were derived. (1) The pile head moment of the model spliced single pile will gradually decrease with the increase of cycles, and the moment of the pile body also decreases with the increase of cycles, which is opposite to the result of full-length model piles. (2) The pile head stiffness of the model spliced single pile is greater than that of a model full-length. Under lateral loading, the disturbance of soil is greater, thus increasing soil density. (3) Piles aligned vertically to lateral forces: In an observation of pile space of 2D, 4D, and 6D, the lateral stiffness of the model spliced pile’s head is greater than that of the model full-length pile’s head, indicating that when spliced piles are under lateral loading, its interaction with the soil creates a greater soil disturbance. (4) Piles aligned parallel to lateral forces: Larger pile spaces create a greater lateral stiffness. But the tendency that lateral stiffness increases with the increase of cycles does not apply to the enlargement of pile spaces. (5) The variation of pile space and the change of mechanical behavior induced by splicing model piles result in a more serious distribution of resistance on spliced group piles than model full-length group piles. The stiffness provided by soil is lower than model full-length group piles, and the generated reciprocal displacement reduction is smaller than that by full-length group piles.
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Chen, Tse-lun, and 陳則綸. "A Study of Size Effect on Single Pile Subjected to Cyclic Lateral Load in Submerged Sand." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/90526174530612823386.
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碩士逢甲大學
土木工程所
100
This research presents the indoor experiment of cyclic lateral load of circular hollow model pile made with aluminum alloy in submerged sand. With different sizes of single pile subjected to cyclic lateral load and the change in outer diameter and the length of pile, this experiment focuses on the effects of cyclic lateral load on bending moment along the piles shaft with change in pile size and the effects of cyclic lateral load on lateral displacement. Base on the result of the experiment on piles with different sizes in submerged sand, the maximum bending moment of all the piles occur at 7.5 times the pile’s outer diameter. Parts of pile’s maximum bending moment decrease with the decrease in the length of pile, and the pile head’s bending moment increase with the decrease in length of pile. The increase in the degree of density of the submerged sand is not obvious alone with the increase in amount of cyclic lateral load.
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LYU, YING-JHONG, and 呂瑩鐘. "A Comparison on the Behavior of Vertical Single Pile and Group Piles between in Submerged Sands and Dry Sands under Cyclic Lateral Load." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/82226573038210073261.
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碩士逢甲大學
土木工程所
98
In this proposed research project, a comparison of the pile behavior under cyclic lateral load in submerged sands and dry sands was to be performed by model pile test. The purpose of this study was to explore the effect of water on the pile behavior as well as to propose suggestions for the design of pile foundation constructed on seabed. A well established model pile testing system was used for this project to perform tests. Comparison of bending moment along pile shaft and lateral displacement of pile head was made. The test results show pile head lateral displacement in submerged sands is greater than that in dry sands, and the pile head lateral displacement are affected by several factors such as the size of pile, the different cyclic lateral load, the number of group piles, and the different alignment of pile groups; in most cases, the maximum bending moment along the pile shaft in submerged sands is usually greater than that in dry sands. In single pile study: in submerged sands and dry sands, the location of maximum bending moment on pile shaft occurred at the depth between 10 times to 15 times of pile outer side length or diameter. In group piles study: in submerged sands, the location of maximum bending moment on pile shaft occurred at the depth between 5 times to 25 times of pile outer side length or diameter; however, in dry sands, the location of maximum bending moment on pile shaft occurred at the depth between 10 times to 15 times of pile outer side length or diameter.
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Ho, Tze-Ling, and 何子寧. "A Study of the Behavior of a Single Pile in Sand Subjected to Cyclic Lateral Load by Laboratory Model Test." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/44577315870723531018.
Full textAbstract:
碩士逢甲大學
土木及水利工程所
92
ABSTRACT While a pile foundation subjected to lateral loadings, its behavior varies with the number of cyclic times and other terms. A study in the influence of cyclic lateral loaded pile with respect to lateral loading forms and soil conditions might reach a further understanding in lateral loaded pile behavior. This study is a lateral loaded single model pile laboratory test, the purpose of this research is to investigate the behavior of a single pile in sand subject to lateral loads, and also compare the influences of different lateral displacement speed, range, pile head confinement, sand density, and lateral loading procedure. With the results of proceeded experiments, several conclusions could be made: (1) In this thesis, model piles were made of aluminum alloy 6061. The maximum bending moment along the model pile is usually occurs somehow closer to the ground line with number of cyclic times, but generally occurs at the depth between 15 times to 20 times of the pile diameter. (2) In the course of 1st lateral loading, soil resistance shows an obvious decrease after the pile head displacement reaches 7mm, but after that the soil resistance increases with number of cyclic time gradually. (3) Lateral displacement speeds shows only slightly influence on model pile behaviors, which might due to soil-pile separation during pile lateral movement, or the influence of soil pressure varies with lateral displacement speed. Among 5 lateral displacement speeds, 0.5mm/sec. shows the greatest effect on pile behavior, while the sped of 0.25mm/sec. show the least effect. (4) With respect to the same displacement range, the one-way cyclic procedure has greater influence then the two-way cyclic procedure. (5) In medium dense sand, the density around the pile increase apparently due to lateral movements, while in dense sand the behavior of model pile differs slightly after cyclic lateral loadings. (6) The Pile head confinement plays a noticeable part in pile behaviors; the partial-fixed pile head contributes only about 80% pile head resistance of fixed-headed pile. (7) Pause-at-two-end lateral loading procedure ensures the soil pressure develop more thoroughly, this could be proved in both pile head resistance and maximum bending moment along the pile. With the increasing number of cyclic times, the behaviors of three lateral loading procedures tend to converge. (8) Base on the subgrade reaction coefficient reduction method proposed by Little and Briaud【21】, and take lateral displacement speed, range, relative density of sand into account, following reduction formula could be obtained : αv= -0.043Ln(v)+0.0376 αD= 0.0279Ln(y/D)+0.0343 αDr=0.3635e -0.0377Dr
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Chen, Wei-Chin, and 陳韋智. "A Study of the Effects of Moment of Inertia and Shape of Pile Cross Section on the Behavior of Pile Groups under Cyclic Lateral Load in Sands by Model Tests." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/64088980842464710709.
Full textAbstract:
碩士逢甲大學
土木工程所
98
In the current study, four different kinds of hollow circular and square model piles with nearly identical moment of inertia were tested under cyclic loading to examine their effect on the behavior of group piles with various spacing and arrangement. It was found the hysteresis loop of pile head displacement and lateral load of a pile group reduces along with the increase of loading cycles. The enclosed area of loop decreases with the increase of moment of inertia of pile cross section. The displacement of pile head for a cycle of loading decreases with the increase of loading cycles. The lateral stiffness at pile head for circular shape of group pile is larger than that of square shape when the loading direction is perpendicular to the center line of a two pile group and the pile having the same spacing. The increase of pile spacing has less effect on the lateral stiffness at pile head. Similar behavior occurred when the center line of a two pile group is parallel to the direction of loading. In addition, group efficiency for a hollow square-shaped pile is nearly the same as that of a hollow circular-shaped pile when the arrangement and spacing are the same.
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Wu, Wei-Ting, and 吳韋霆. "A Study of the Effects of Multiple Welding Points on the Behavior of Model Spliced Pile in Sand under Cyclic Lateral Load." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/45722559147913477153.
Full textAbstract:
碩士逢甲大學
土木工程所
95
This research investigated the behavior of model spliced single pile, and group spliced piles with two weld points in sand under cyclic lateral load. And the results were compared with those obtained from previous investigation for single point spliced pile and non-spliced pile with the same length and pile cross-section. According to the test results, the following conclusions are summarized as below. (1) The bending moment at the head of the model single pile decreases gradually, with the increase of cycles, for three types of pile. (2) With the increase of cycles, the lateral stiffness at the head of the model spliced single pile for two weld points is obvious greater than that of a non-spliced full-length model single pile ,but it less than the model spliced single pile for one weld point. (3) Two piles in line aligned vertically to lateral force, in the condition of pile space of 2D, 4D, and 6D, with the increase of the pile space, the lateral stiffness at the head of the model spliced group piles for two weld points, is gradually greater than the non-spliced full-length model group piles, but it still less than the model spliced group piles for one weld point. (4) Two piles in line aligned horizontal to lateral force, with the increase of pile space, and the effects of the number of welding points, the bending moment produced by the model spliced group piles for two weld points, the model spliced group piles for one weld point ,and the non-spliced full-length model group piles has apparent diverseness. (5) Two piles in line aligned horizontal to lateral force, in the condition of pile space of 6D, 8D, and 12D, the lateral stiffness at the head of the model spliced group piles for two weld points is greater than the model spliced group piles for one weld point, and a non-spliced full-length model group piles.
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Liao, Fang-I., and 廖方意. "A Study of the Effects of Moment of Inertia and Shape of Pile Cross Section on the Behavior of a Single Pile under Cyclic Lateral Load in Sands by Model Tests." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/88909274864865819206.
Full textAbstract:
碩士逢甲大學
土木工程所
95
To confer the influence of pile behavior with the change of cross section shape and area moment of inertia, the indoor model tests had been performed in this study, which used lateral cyclic loading to exerted on the single pile with the different area moment of the inertia of circular and square cross section, and on the single hollow pile with the same area moment of inertia of circular and square cross section. The test results revealed that with the number of cycles gradually increased, the bending moment of circular and square hollow pile at the head will tend to decrease, and the smaller the area moment of inertia are, the decrease will be more conspicuous. And with the number of cycles increased, the bending moment will become larger, but the bending moment decreased when hollow circular pile''s outer diameter was 44.78mm and when the hollow square pile was 19mm in perimeter. With the moment of inertia increase, the bending moment won’t be influenced by the increase of the number of cycles. Because the head of the pile isn’t fixed completely, the maximum bending moment won’t occur at the head of the pile. For the circular and square hollow pile, the lateral stiffness at the head of the pile will increase when the moment of inertia increase. When pushing the pile, the lateral stiffness is larger than pulling, and under the cyclic lateral loading the lateral stiffness at the head of pile will tend to be the same.
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林庭輝. "Analysis of offshore piles under cyclic lateral loads." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/45922231219861232715.
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Hui, Lin Ting, and 林庭輝. "Analysis of Offshore Piles under Cyclic Lateral Loads." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/34642488917157887033.
Full textAbstract:
碩士國立臺灣科技大學
營建工程技術學系
81
The aim of the research is to study the interaction relationships between soil and offshore pile under undrained cyclic loads. Static P-Y curves are modified to reflect the effects of cyclic lateral loads. The analytic method condiders the increase of the initial pilelateral capacity due to higher load rate, and then condiders the modulus and strength degradation characterictics of soil around the pile under cyclic loads to determine the modification of P-Y curve. The computer program CYCLAT developed using the above algorithm was used to study the cyclic test results of the Houston and Texas full scale model piles. Predictions of the cyclic lateral behavior of the foundation pile anchoring the Guo-Guang production platform (CBK-11) were made. In addition, parametric studies were conducted to understand the relative significance of various relevant parameters on the cycliclateral pile behavior. Analytical results show good agreement with pile test data. The lateral capacity of offshore piles decrease as cyclic lateral loading progresses. The decrease in capacity is usually accomjpanied by an increase in lateral deflections at pile top. In particular, when the pile is close to failure the pile top deflections will increase rapidly. Resutls from the parametric study show htat the most significant factors affecting the undrained cyclic pile behavior are the magaitude of the loading rate and the soil strength degradation. On the other hand, the degradation of soil modulus have much less effect.
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夏國柱. "A study of factors influencing offshore pile behavior under cyclic axial loads." Thesis, 1992. http://ndltd.ncl.edu.tw/handle/62040237312465964139.
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Ti-YingHuang and 黃迪瑩. "Deformation Responses of Piles in Cohesionless Soil under Cyclic Axial Tension Loads." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/swp85j.
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Vazinkhoo, Saman. "Modelling of single vertical piles subjected to monotonic and cyclic lateral loads and free-field movements." Thesis, 1996. http://hdl.handle.net/2429/5694.
Full textAbstract:
In the past twenty years, many researchers and practitioners have become interested in the behaviour
of piles under lateral loading conditions. Although piles are generally used to carry axial loads,
quite often, such as in the case of seismic loads and/or lateral loads caused by ground displacement,
they are required to carry lateral loads. The ability to predict the performance of piles under lateral
loading caused by earhquakes is very important and is the focus of this thesis. To date very few and
limited modelling techniques have been developed based on data obtained from testing of full size
piles. This is due to the high costs involved with performing comprehensive experiments on
prototype piles.
The response of piles to lateral loads may be analyzed using different methods ranging from
complex 3-D finite element techniques to simple closed-form solutions for an elastic beam on an
elastic foundation. This thesis employs the modulus of subgrade reaction approach due to its
versatality and ease of use.
In the last five years, large amount of data from pile lateral load tests have become available.
In this thesis, the available methods and models for analysing laterally loaded vertical piles are first
reviewed and then two new models are developed. The first is a new cyclic P-y curve model based
on the Hydraulic Gradient Similitude (HGS) tests carried out by Yan (1990). Then a new numerical
model is developed which incorporates the first model and other P-y curves for analysis of laterally
loaded vertical piles. The new numerical model is incorporated into the computer program CYCPILE which is calibrated and verified using the available test data. In general, excellent
agreement between the model predictions and the test data is obtained.