循环荷载下单桩-土-桩帽共同作用分析

严 敏; 李 波; 李 炜

doi:10.11988/ckyyb.20140541

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长江科学院院报 ›› 2015, Vol. 32 ›› Issue (12) : 76-81. DOI: 10.11988/ckyyb.20140541

岩土工程

循环荷载下单桩-土-桩帽共同作用分析

严敏¹,李波¹,李炜^2,3

作者信息 +

Analysis of Interaction of Single Pile-soil-cap in Layered Foundationunder Cyclic Loading

YAN Min¹, LI Bo¹, LI Wei^2,3

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文章历史 +

摘要

为探究循环往复荷载作用下层状地基中单桩-土-桩帽的共同作用,基于Mindlin板理论和层状弹性地基模型,结合层状地基中单桩的荷载传递规律,提出一种分析共同作用的方法。首先建立单桩-土-桩帽共同作用刚度矩阵,并利用循环往复荷载下土体压缩模量的衰减特性得到带台单桩的累积沉降及单桩-土-桩帽整体刚度的变化趋势,在此基础上进一步开展算例验证和参数分析。结果表明:计算结果与Butterfield的解非常一致;单桩-土-桩帽整体刚度明显大于单桩刚度,增加单桩的弹性模量可以显著地提高单桩-土-桩帽的整体刚度;当桩径确定时,桩长存在一个最优值使得整体刚度最大;而当桩的长径比大于某一值时,桩长的增加对整体刚度及桩帽的荷载分担比影响较小;循环往复荷载作用下单桩-土-桩帽的整体刚度逐渐增大,且趋于稳定值。

Abstract

A simplified analytical approach was proposed to study on the interaction of single pile-soil-cap (SPSC)under cyclic loading in layered soils, combined with the theory of Mindlin plate theory and elastic foundation model, as well as the law of load transfer of single pile. At first, we established the stiffness matrixes for interaction of SPSC and predicted the accumulative settlement of the single pile with cap and variation of SPSC global stiffness through employing attenuation of compressive modulus. Then, on the basis of this, we carried out cases verification and parameters analysis. The results show that, calculated data by the method in this paper is well consistent with those by Butterfield method; furthermore, the global stiffness of the SPSC is significantly greater than that of the single pile because of the addition of the pile cap, and the increase of elastic modulus of the pile can obviously strengthen the global stiffness; meanwhile, there exists an optimum value range of the length of a pile for a given diameter, and the increase of the length of pile has less influence on the global stiffness of the SPSC and the bearing load ratio of the cap when the ratio of length to diameter of pile is larger than a determined value; finally, the global stiffness of the SPSC gradually increased with the cyclic count until the stiffness is up to a stable value.

导出引用

严敏,李波,李炜. 循环荷载下单桩-土-桩帽共同作用分析[J]. 长江科学院院报. 2015, 32(12): 76-81 https://doi.org/10.11988/ckyyb.20140541

YAN Min, LI Bo, LI Wei. Analysis of Interaction of Single Pile-soil-cap in Layered Foundationunder Cyclic Loading[J]. Journal of Changjiang River Scientific Research Institute. 2015, 32(12): 76-81 https://doi.org/10.11988/ckyyb.20140541

中图分类号： TU473

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