scholarly journals Numerical Study for Centrifugal Model Tests of a Single Pile Foundation Installed in Sandy Deposits

2007 ◽  
Vol 23 (4) ◽  
pp. 389-398 ◽  
Author(s):  
C. W. Lu

AbstractIt is believed that a dynamic analysis is urgently required to provide a more reliable numerical method for seismic evaluation of a full system, which includes foundation, super structure, and ground in earthquake zones such as Taiwan and Japan. A centrifugal model test of pile foundation is simulated numerically using a three-dimensional finite-element model (3D-FEM) code in this study. In the numerical simulation, parameters of the sandy soils in tij model that are derived from accumulated experiences in static tests are first calibrated by centrifugal vibration tests of sandy ground. Model tests of a single pile foundation installed in grounds of same unit weight of soil as in the static tests are then simulated using the calibrated parameters. The numerical simulation resulted in a good agreement with the corresponding physical model tests. By comparing the computed and the observed results, one can find and confirm that it is necessary to employ an appropriate soil model to reproduce dynamic soil behavior due to major vibration. Representation of pile by beam element in the numerical analysis is applicable when attention is paid on the response acceleration of top of pile foundation, on soils at some distances to the pile foundation, and on bending moment of the pile in a stiffer ground. Equal-displacement boundary condition for two-side boundaries is proven to be efficient. To reduce the computation time, the assumption of a constant damping of viscous matrix is acceptable.

2011 ◽  
Vol 71-78 ◽  
pp. 4460-4462
Author(s):  
Ya Dong Chen ◽  
Xu Dong Wang ◽  
Yue Xin She ◽  
Jiang Dong Cai

ABAQUS is used to study the load-settlement characteristic and soil displacement field of the pile raft foundation. Numerical results are compared to the outputs from model test. The study results show that good consistency is obtained from the comparison of results between numerical simulation and model tests. Small pile space will weaken the single pile bearing capacity. The compress region is mainly centralized in the soil beneath the pile tip to the 3b space pile raft foundation, which presents a massive deep foundation failure pattern. As the increase of pile space, the compress region under cap shifts upward. The displacement influence depth of 6b space pile foundation is smaller than 3b space pile raft foundation, and it is destroyed by the lateral squeeze of the soil around piles.


2011 ◽  
Vol 374-377 ◽  
pp. 1947-1952 ◽  
Author(s):  
Zhao Yun Xiao ◽  
Guo Xun Zhang ◽  
Wei Xu ◽  
Zhong Ming Xue

It is a complicated progress of interaction between pile and soil when pile is under both vertical load and horizontal load. This paper analyzes the variation of stress, strain, deformation and deflection of the pile body by finite element numerical simulation of single bored concrete pile under vertical load together with horizontal load. Based on the existing research results, conclusions could be that the vertical load can increase horizontal bearing capacity of the pile in sandy soils, but horizontal bearing capacity of the pile in clayey soils is more complicated. Hope that the simulation can provide some references for the design of pile foundation.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ke Chen

Pile foundation settlement is a kind of foundation form. In recent years, because of the increasing population and economic development in China, high-rise buildings have emerged in people’s vision. Due to the development of engineering construction, the type and technology of pile foundation, as well as the control and detection of the single pile and pile group have been greatly improved. In view of the influence of pile foundation settlement on the surrounding environment of high-rise buildings, this paper mainly studies from the angle of single pile settlement and pile group settlement. According to the construction method of pile foundation, the static pressure sinking pipe cast-in-place pile can produce soil squeezing effect in pile foundation construction. The experimental analysis was carried out. According to the engineering example, finite element numerical simulation is used to analyze the influence degree of pile foundation settlement on adjacent buildings with and without raft, and the feasibility and correctness of numerical simulation are analyzed by comparing the simulation results with the measured values. This paper mainly studies the influence of pile foundation settlement of high-rise buildings on surrounding buildings from the aspects of problems and solutions.


2020 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Hitoshi Tanaka ◽  
Nguyen Xuan Tinh ◽  
Xiping Yu ◽  
Guangwei Liu

A theoretical and numerical study is carried out to investigate the transformation of the wave boundary layer from non-depth-limited (wave-like boundary layer) to depth-limited one (current-like boundary layer) over a smooth bottom. A long period of wave motion is not sufficient to induce depth-limited properties, although it has simply been assumed in various situations under long waves, such as tsunami and tidal currents. Four criteria are obtained theoretically for recognizing the inception of the depth-limited condition under waves. To validate the theoretical criteria, numerical simulation results using a turbulence model as well as laboratory experiment data are employed. In addition, typical field situations induced by tidal motion and tsunami are discussed to show the usefulness of the proposed criteria.


2013 ◽  
Vol 444-445 ◽  
pp. 1574-1578 ◽  
Author(s):  
Hua Hua Xiao ◽  
Zhan Li Mao ◽  
Wei Guang An ◽  
Qing Song Wang ◽  
Jin Hua Sun

A numerical study of premixed propane/air flame propagation in a closed duct is presented. A dynamically thickened flame (TF) method is applied to model the premixed combustion. The reaction of propane in air is taken into account using a single-step global Arrhenius kinetics. It is shown that the premixed flame undergoes four stages of dynamics in the propagation. The formation of tulip flame phenomenon is observed. The pressure during the combustion process grows exponentially at the finger-shape flame stage and then slows down until the formation of tulip shape. After tulip formation the pressure increases quickly again with the increase of the flame surface area. The vortex motion behind the flame front advects the flame into tulip shape. The study indicates that the TF model is quite reliable for the investigation of premixed propane/air flame propagation.


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