scholarly journals Subdomain Method for Layout Optimization of Piles in a Composite Pile Foundation

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Kun Cai
Keyword(s):  
Pile Foundation ◽  
Layout Optimization ◽  
Subdomain Method ◽  
Composite Pile

scholarly journals Bearing Characteristics of Composite Pile Group Foundations with Long and Short Piles under Lateral Loading in Loess Areas

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Tianzhong Ma ◽  
Yanpeng Zhu ◽  
Xiaohui Yang ◽  
Yongqiang Ling
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Horizontal Displacement ◽  
Pile Group ◽  
Lateral Load ◽  
Test Model ◽  
Pile Head ◽  
Load Bearing ◽  
Composite Pile ◽  
Pile Length

It is very necessary to research the bearing characteristics of composite pile group foundations with long and short piles under lateral load in loess areas, because these foundations are used widely. But few people researched this problem in loess areas up to now worldwide. In this paper, firstly, an indoor test model of a composite pile foundation with long and short piles is designed and then employed to explore the vertical load bearing characteristics and load transfer mechanisms of a single pile, a four-pile group, and a nine-pile group under different lateral loads. Secondly, ANSYS software is employed to analyze the load-bearing characteristics of the test model, and for comparison with the experimental results. The results demonstrate the following. (1) The lateral force versus pile head displacement curves of the pile foundation exhibit an obvious steep drop in section, which is a typical feature of piercing damage. A horizontal displacement limit of the pile foundation is 10 mm and 6mm for the ones sensitive to horizontal displacement. (2) The axial force along a pile and frictional resistance do not coincide, due to significant variations and discontinuities in the collapsibility of loess; a pile body exhibits multiple neutral points. Therefore, composite pile groups including both long and short piles could potentially maximize the bearing capacity and reduce pile settlement. (3) The distribution of stress and strain along the pile length is mainly concentrated from the pile head to a depth of about 1/3 of the pile length. If the lateral load is too large, short piles undergo rotation about their longitudinal axis and long piles undergo flexural deformation. Therefore, the lateral bearing capacity mainly relies on the strength of the soil at the interface with the pile or the horizontal displacement of the pile head.

scholarly journals Calculation of Bearing Capacity and Deformation of Composite Pile Foundation with Long and Short Piles in Loess Areas

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Tianzhong Ma ◽  
Yanpeng Zhu ◽  
Xiaohui Yang
Keyword(s):  
Theoretical Calculation ◽  
Bearing Capacity ◽  
Pile Foundation ◽  
Frictional Resistance ◽  
Operating Conditions ◽  
Neutral Point ◽  
Pile Foundations ◽  
Single Pile ◽  
Deformation Control ◽  
Composite Pile

In order to calculate the bearing capacity and settlement deformation of composite pile foundations with long and short piles in collapsible loess areas, the theoretical approximate solution was used to obtain the location of the neutral point of single piles. Additionally, based on the equation to calculate the bearing capacity of multielement composite foundations, a method considering the negative frictional resistance was proposed for calculating the bearing capacity of composite pile foundations with long and short piles. Based on the shear displacement method and the principle of deformation control, an equation to calculate the displacement and deformation of a composite pile foundation was presented. A model test with different operating conditions, i.e., a single pile, four piles, and eight piles, was designed to verify the proposed calculation methods. The results show that the location of the neutral point has a significant influence on the single-pile negative frictional resistance, and the neutral point ratio of the calculation meets the value range of the practical project. When the load at the top of the pile is relatively small, the experimental curve is consistent with the theoretical calculation curve, whereas when the load is comparatively large, the theoretically calculated displacement increase at the top of the pile is greater than the measured one. Under the premise that the theoretical calculation is in good agreement with the results, the theoretical value is larger than the actual value. And it contributes to strengthening engineering safety.

Composite Pile Foundation in Bridge: Code recommendation and Chilean experience

2017 ◽  
Vol 109 (2) ◽  
pp. 3476-3483
Author(s):  
Pablo Trucco ◽  
Matias A Valenzuela
Keyword(s):  
Pile Foundation ◽  
Composite Pile

scholarly journals Numerical analysis for the vertical bearing capacity of composite pile foundation system in liquefiable soil under sine wave vibration

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248502
Author(s):  
Huang Zhan-fang ◽  
Xiao-hong Bai ◽  
Chao Yin ◽  
Yong-qiang Liu
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Water Pressure ◽  
Seismic Loading ◽  
Shaking Table ◽  
Pile Spacing ◽  
Liquefiable Soil ◽  
Composite Pile ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity

Composite pile foundation has been widely used in ground engineering. This composite pile foundation system has complex pile-soil interactions under seismic loading. The calculation of vertical bearing capacity of composite pile foundation is still an unsolved problem if the soil around piles is partially or completely liquefied under seismic loading. We have completed indoor shaking table model tests to measure the vertical bearing capacity in a liquefiable soil foundation under seismic loading. This paper will use a numerical approach to analyze the change of this vertical bearing capacity under seismic loading. Firstly, the Goodman contact element is improved to include the Rayleigh damping. Such an improvement can well describe the reflection and absorption of seismic waves at the interface of soil and piles. Secondly, the Biot’s dynamic consolidation theory incorporated an elastoplastic model is applied to simulate the soil deformation and the generation and accumulation of pore water pressure under seismic loading. Thirdly, after verification with our indoor shaking table test data, this approach is used to investigate the effects of pile spacing on liquefaction resistance of the composite pile foundation in liquefiable soil. The time histories of pore water pressure ratio (PPR′) are calculated for the liquefiable soil and the vertical bearing capacity in partially liquefied soil is calculated and compared with our indoor shaking table test data at the 3D, 3.5D, 4D, 5D and 6D cases (D is the pile diameter). It is found that the pile spacing has some influence on the extent of soil liquefaction between piles. The vertical bearing capacity varies with liquefaction extent of inter-pile soil. The optimization of pile spacing varies with liquefaction extent. These results may provide some reference for the design of composite pile foundation under seismic loading.

Based on the Reliability of Composite Pile Foundation Design Theory Research

2013 ◽  
Vol 821-822 ◽  
pp. 1277-1284
Author(s):  
Wen Ting Zhao ◽  
De Zhi Kong ◽  
Hai Fei Zhang
Keyword(s):  
Physical Properties ◽  
Pile Foundation ◽  
Design Theory ◽  
Design Method ◽  
Limit State ◽  
Allowable Stress ◽  
Foundation Design ◽  
Probability Limit ◽  
Composite Pile ◽  
Theory Research

Due to the physical properties of the soil between piles discrete，thus，composite pile foundation 's bearing capacity exists some uncertainty. So far, the study of the reliability of composite pile foundation is transform from the allowable stress method to the probability limit state design method. That is to say probability definite value design method. Therefor , determine the resistance subentry coefficient become the key of the design method. This paper introduces the significance of the subentry coefficient and the subentry coefficient of the composite pile foundation. Through the calculation of engineering examples, this article give the values of the subentry coefficient and provide a reference for the design of composite pile later.

scholarly journals Application of extended end composite pile design in pile foundation work

2017 ◽  
Vol 170 (5) ◽  
pp. 455-465 ◽  
Author(s):  
Seungho Kim ◽  
Seoung-Wook Whang ◽  
Sangyong Kim ◽  
Won Gil Hyung
Keyword(s):  
Pile Foundation ◽  
Pile Design ◽  
Composite Pile
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