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The time-dependent behaviour of clay during cylindrical cavity expansionAli, Faisal Haji January 1984 (has links)
No description available.
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Dynamic Analysis on floating pier of landing stageChen, Liang-yin 25 August 2005 (has links)
In this thesis, two-dimensional floating pier consists of single rectangular impermeable pontoon and rigid beam is studied. The purpose of this study is to present a theoretical solution for linearlized problem of incident waves acting on a floating pier with pile-restrained. All boundary conditions are linearlized in the problem which is separated into a scattering problem and radiation problem with unit motion amplitude. The method of separation of variables is used to solve for velocity potentials. For the radiation problem with unit heave and rotate amplitude, the boundary value problem with nonhomogeneous boundary condition beneath the structure is solved by using a solution procedure proposed by Lee(1995). By calculating wave force from velocity potential, and equations of motion of the floating structure, an analytic solution for the problem is developed. At last, using finite element method to calculate the dynamic analysis on the pile acting by the pontoon and incident waves.
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Negative friction on piled foundationsNicholls, R. A. January 1973 (has links)
No description available.
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The response of vertical piles to lateral loading and momentFulthorpe, J. N. January 1986 (has links)
No description available.
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Ground compaction due to vibrodriving of pilesBement, R. A. P. January 1996 (has links)
Civil engineering construction frequently requires the use of piles to carry structural loads to stronger ground strata or to control lateral ground movements. A variety of techniques are available to install piles into the ground. Of central interest to this research is the vibratory hammer, or vibrodriver, which is the preferred method used to drive piles into granular soils. .The installation of sheet and bearing piles by vibrodriver causes periodic vibration in the adjacent ground which is severe very close to the piles, but attenuates with distance. A potential consequential effect of the vibrations that are caused by vibrodriving is ground compaction, which may be observed as differential surface settlement. It is desirable that vibration induced ground compaction settlement should be estimated for contracts where loose to medium-dense granular soils occur, especially when buildings on shallow foundations or poorly bedded service pipes are adjacent. It is unlikely that a simple in-situ soils test will allow accurate, specific estimates, but rather that a range of vibratory tests should be performed which can then be used as a knowledge base. Settlement trends and associated parameters can then be identified which will allow the prediction of settlement with reference to the in-situ soil and the ground vibration data. This argument forms the basis of the laboratory test programme. A range of granular soils were studied using an adapted 150mm Rowe cell (a hydraulic oedometer). Use of the Rowe cell enabled samples to experience compaction under effective stress conditions that are appropriate for equivalent soils in the field. The complete cell was mounted on an electromagnetic shaker and after static consolidation, the samples were vibrated under maintained hydraulic load, at frequencies and accelerations that are appropriate for soils adjacent to vibrodrivers. Change in sample height was recorded for controlled vertical (and horizontal) vibrations, typically in the range of 0.lg to 5.0g at 25Hz and 40Hz. Soils were tested under a range of effective stresses and moisture content. The results of the laboratory programme and subsequent data analysis are presented in tables and diagrams. Expressions that describe a good relationship between acceleration, soil type, relative density and static load allow upperbound estimates of vibratory settlements to be made for accelerations of up to 6.0g. An additional expression is presented that accounts for the influence of moisture content, ground vibration frequency and vibration duration. Summary tables are presented that define categories of vibration induced ground compaction settlement based on settlement potential, risk and severity. The use of the settlement equations and the influence of various parameters are demonstrated for a range of example applications, hi addition, data is abstracted from case studies found in the literature and sites that were visited during the research. The abstracted data are then used to perform settlement estimates which are compared to the reported examples. Good correlation between observed and calculated settlement is demonstrated in many cases. However, in some instances, it appears that ground settlements were exacerbated by at least one additional mechanism, such as cumulative pore water pressure increase, or lateral movement of sheet piles, in addition, extraction of piles by vibrodriver appears to contribute significantly to the reported cases of ground settlement.
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Modèle optoélectronique pour la conception de piles solaires à semiconducteur.Suau, Jean-Claude, January 1900 (has links)
Th. 3e cycle--Électronique, électrotech., autom.--Toulouse 3, 1977. N°: 1966.
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The non-destructive testing of model piles using a resonant vibration techniqueLilley, D. M. January 1982 (has links)
No description available.
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Uplift resistance of foundationsRay Chaudhuri, Kiriti Prosad January 1977 (has links)
No description available.
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Influence of Pile Shape on Resistance to Lateral LoadingBustamante, Guillermo 01 December 2014 (has links) (PDF)
The lateral resistance of pile foundations has typically been based on the resistance of circular pipe piles. In addition, most instrumented lateral load tests and cases history have involved circular piles. However, piles used in engineering practice may also be non-circular cross-section piles such as square and H piles. Some researchers have theorized that the lateral resistance of square piles will be higher than that of circular piles (Reese and Van Impe, 2001; Briaud et al, 1983; Smith, 1987) for various reasons, but there is not test data to support this claims. To provide basic comparative performance data, lateral load tests were performed on piles with circular, square and H sections. To facilitate comparisons, all the tests piles were approximately 12 inches in width or diameter and were made of steel. The square and circular pipe sections had comparable moments of inertia; however, the H pile was loaded about the weak axis, as is often the case of piles supporting integral abutments, and had a much lower moment of inertia. The granular fill around the pile was compacted to approximately 95% of the standard Proctor maximum density and would be typical of fill for a bridge abutment. Lateral load was applied with a free-head condition at a height of 1 ft above the ground surface. To define the load-deflection response, load was applied incrementally to produce deflection increments of about 0.25 inches up to a maximum deflection of about 3 inches. Although the square and pipe pile sections had nearly the same moment of inertia, the square pile provided lateral resistance that was 20 to 30% higher for a given deflection. The lateral resistance of the H pile was smaller than the other two pile shapes but higher than what it is expected based on the moment of inertia. Back analysis with the computer program LPILE indicates that the pile shape was influencing the lateral resistance. Increasing the effective width to account for the shape effect as suggested by Reese and Van Impe (2001) was insufficient to account for the increased resistance. To provide agreement with the measured response, p-multipliers of 1.2 and 1.35 were required for the square pile and H piles, respectively. The analyses suggest that the increased resistance for the square and H pile sections was a result of increases in both the side shear and normal stress components of resistance. Using the back-calculated p-multipliers provided very good agreement between the measured and computed load-deflection curves and the bending moment versus depth curves.
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Timber pile-supported road embankment : Numerical and analytical analysis of field monitoring project E4 RåneåNystedt, Kent January 2022 (has links)
The previous E4 Råneå road embankment was prone to flooding. Risk of flooding in combination with settlements of the road due to the weak underlying sulphide soil was problematic. The Swedish Transportation Administration improved the length section E4 Råneå by rebuilding the road using the method light embankment piling. The centre-to-centre pile distance was chosen to 1.1 m and embankment height 1.8 m. The embankment is reinforced with geosynthetic reinforcements resting on timber piles, which were installed on till stratum. Two geosynthetics were installed, with their strength properties in opposite direction from each other. Their purpose was to stiffen the soil and reduce loading on the weak sulphide subsoil. Field monitoring equipment were placed in the road to measure the behavior before and after consolidation. To validify the results, used instruments in this thesis concerns: pressure cells, extensometers, piezometers and a hydrostatic profile gauge. The Swedish Transport administration wants to evaluate if an increase in piling distance is possible. From the conventional practice of maximum 1.2 m to 1.4 m. It is also interesting if the increased pile distance holds for a taller embankment of 2.5 m. Answering this would aid in increasing the cost-effectiveness of light embankment piling. The performed investigation has been done in the finite element analysis program Plaxis 3D 2021 by simulating half of an embankment with supplementary load model. To capture field behavior, PLAXIS SoilTest has been used to calibrate the compressive material parameters obtained in oedometer testing. The geosynthetics have been modeled with regards to creep and their stiffness increase on surrounding soil due to interlocking of soil particles. Guaranteeing the reliability of the numerical analysis was made by a comparison of the base model to field monitoring equipment before conducting the parametric study. The base numerical model was reliable in capturing the result of field monitoring equipment. Deviations in pile loads was observed beneath the light trafficked road lane. Conducting the parametric study, the results indicated an increase in pile head loading, total settlements, differential settlements, and deformations in the geosynthetic reinforcement when pile distance and embankment height increased. With a taller embankment of 2.5 m and increased pile distance of 1.4 m numerical simulated pile head loads were in sizes of the design pile strength. Tensile stress in the geosynthetic reinforcement was below long-term design strength. The ratio pile efficacy, that is how effective the structure is at reducing sub soil load has been evaluated in the parametric study at three unit cells. A logarithmic growth is observed when reducing the pile distance at the middle of the road with consistent behavior between embankment height. When studying cells beneath the heavy trafficked lane a linear relationship could be seen instead. This study suggests it is possible to perform the increase in pile distance of 1.4 m for the current embankment height 1.8 m, but needs to be investigated further for the 2.5 m high embankment.
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