The Differential Settlement in Rigid Pile Composite Foundation on Collapsible Loess in High Speed Railway

2012 ◽  
Vol 12 (1) ◽  
pp. 46-51
Author(s):  
Changdan Wang ◽  
Binglong Wang ◽  
Shunhua Zhou ◽  
Hui Su
Keyword(s):  
High Speed ◽  
Differential Settlement ◽  
Composite Foundation ◽  
High Speed Railway ◽  
Rigid Pile ◽  
Collapsible Loess ◽  
Rigid Pile Composite Foundation

Comparative Analysis on Neutral Point Distribution in Rigid Pile Composite Foundation on Collapsible Loess in High Speed Railway

2011 ◽  
Vol 90-93 ◽  
pp. 471-476
Author(s):  
Chang Dan Wang ◽  
Hui Su ◽  
Chun Hua Zou
Keyword(s):  
High Speed ◽  
Neutral Point ◽  
Composite Foundation ◽  
Stable Range ◽  
Point Distribution ◽  
Pile Spacing ◽  
Rigid Pile ◽  
Collapsible Loess ◽  
Pile Cap ◽  
Rigid Pile Composite Foundation

To research and analyze the neutral point distribution of rigid pile composite foundation on collapsible loess ground in high speed railway, the centrifuge model tests are used to imitate pile raft composite foundation and pile net composite foundation in different pile spacing based on the experimental study at home and abroad. The research results show that the movement of negative skin friction and the position of neutral point which is drop conspicuously with larger pile spacing are a continuous changing process in composite foundation. In the pile spacing 2D,4D,6D of pile raft composite foundation, the stable range of neutral point position are 0.25(the pile length ratio), 0.59,0.63 separately in post-construction stage. In the pile spacing 2D(no pile-cap),4D(no pile-cap),4D(pile-cap),6D(pile-cap) of pile net composite foundation, the stable range of neutral point position are 0.37to0.43(the pile length ratio),0.50,0.80,0.81separately in post-construction stage. The pile-cap setting has more influence on Neutral point distribution. Suggestions are given that the waterproof and drainage measures in foundation must be considered when setting up composite foundation on collapsible loess.

Character Analysis of Balance and Imbalance of Varying Rigidity of Rigid Pile Composite Foundation under Seismic Load

2014 ◽  
Vol 1065-1069 ◽  
pp. 19-22
Author(s):  
Zhen Feng Wang ◽  
Ke Sheng Ma
Keyword(s):  
Finite Element ◽  
Bending Moment ◽  
Horizontal Displacement ◽  
Element Model ◽  
Composite Foundation ◽  
Seismic Load ◽  
Seismic Loads ◽  
Element Analysis ◽  
Rigid Pile ◽  
Rigid Pile Composite Foundation

Based on ABAQUS finite element analysis software simulation, the finite element model for dynamic analysis of rigid pile composite foundation and superstructure interaction system is established, which selects the two kinds of models, by simulating the soil dynamic constitutive model, selecting appropriate artificial boundary.The influence of rigid pile composite foundation on balance and imbalance of varying rigidity is analyzed under seismic loads. The result shows that the maximum bending moment and the horizontal displacement of the long pile is much greater than that of the short pile under seismic loads, the long pile of bending moment is larger in the position of stiffness change. By constrast, under the same economic condition, the aseismic performance of of rigid pile composite foundation on balance of varying rigidity is better than that of rigid pile composite foundation on imbalance of varying rigidity.

scholarly journals Simplified analytical solution for stress concentration ratio of piled embankments incorporating pile–soil interaction

2021 ◽  
Author(s):  
Qiang Luo ◽  
Ming Wei ◽  
Qingyuan Lu ◽  
Tengfei Wang
Keyword(s):  
Stress Concentration ◽  
Analytical Solution ◽  
High Speed ◽  
Concentration Ratio ◽  
Differential Settlement ◽  
Fundamental Parameter ◽  
Soil System ◽  
Rigid Pile ◽  
Stress Concentration Ratio ◽  
Piled Embankments

AbstractPiled embankments have been extensively used for high-speed rail over soft soils because of their effectiveness in minimizing differential settlement and shortening the construction period. Stress concentration ratio, defined as the ratio of vertical stress carried by pile heads (or pile caps if applicable) to that by adjacent soils, is a fundamental parameter in the design of piled embankments. In view of the complicated load transfer mechanism in the framework of embankment system, this paper presents a simplified analytical solution for the stress concentration ratio of rigid pile-supported embankments. In the derivation, the effects of cushion stiffness, pile–soil interaction, and pile penetration behavior are considered and examined. A modified linearly elastic-perfectly plastic model was used to analyze the mechanical response of a rigid pile–soil system. The analytical model was verified against field data and the results of numerical simulations from the literature. According to the proposed method, the skin friction distribution, pile–soil relative displacement, location of neural point, and differential settlement between the pile head (or cap) and adjacent soils can be determined. This work serves as a fast algorithm for initial and reasonable approximation of stress concentration ratio on the design aspects of piled embankments.

Analysis for Seismic Response of Compacted Soil-Cement Pile Composite Foundations

2011 ◽  
Vol 368-373 ◽  
pp. 456-460
Author(s):  
Hong Huan Cui ◽  
Li Qun Zhang ◽  
Hai Long Wang
Keyword(s):  
Seismic Response ◽  
Seismic Design ◽  
Seismic Behavior ◽  
Composite Foundation ◽  
Response Analysis ◽  
Compacted Soil ◽  
Rigid Pile ◽  
Soil Cement ◽  
Earthquake Load ◽  
Rigid Pile Composite Foundation

Compacted soil-cement pile possess the excellences both flexible pile and rigid pile. The composite foundation of compacted soil-cement pile are getting more and more applicable to construction． However, the research on their response under dynamic load, especially under earthquake load，is quite limited．Now the seismic response analysis in time domain is performed with finite element method(ABAQUS).Some parameters influencing the anti-seismic behavior of half-rigid pile composite foundation are studied． Based on these research , some conclusions which may be of some value for anti-seismic design of this type of composite foundations are drawn．

scholarly journals Effect of Bridge-Pier Differential Settlement on the Dynamic Response of a High-Speed Railway Train-Track-Bridge System

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaohui Zhang ◽  
Yao Shan ◽  
Xinwen Yang
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Tensile Force ◽  
Differential Settlement ◽  
Bridge Pier ◽  
Vertical Acceleration ◽  
Train Track ◽  
Allowable Limit ◽  
High Speed Railway ◽  
Track Bridge

A model based on the theory of train-track-bridge coupling dynamics is built in the article to investigate how high-speed railway bridge pier differential settlement can affect various railway performance-related criteria. The performance of the model compares favorably with that of a 3D finite element model and train-track-bridge numerical model. The analysis of the study demonstrates that all the dynamic response for a span of 24 m is slightly larger than that for a span of 32 m. The wheel unloading rate increases with pier differential settlement for all of the calculation conditions considered, and its maximum value of 0.695 is well below the allowable limit. Meanwhile, the vertical acceleration increases with pier differential settlement and train speed, respectively, and the values for a pier differential settlement of 10 mm and speed of 350 km/h exceed the maximum allowable limit stipulated in the Chinese standards. On this basis, a speed limit for the exceeding pier differential settlement is determined for comfort consideration. Fasteners that had an initial tensile force due to pier differential settlement experience both compressive and tensile forces as the train passes through and are likely to have a lower service life than those which solely experience compressive forces.

Centrifuge study on behavior of rigid pile composite foundation under embankment in soft soil

2020 ◽  
Author(s):  
Jian-lin Yu ◽  
Jia-jin Zhou ◽  
Xiao-nan Gong ◽  
Ri-qing Xu ◽  
Jun-yuan Li ◽  
...  
Keyword(s):  
Soft Soil ◽  
Composite Foundation ◽  
Rigid Pile ◽  
Rigid Pile Composite Foundation
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