往复荷载下层状地基柔性筏板-群桩共同作用分析  

Analysis of interaction mechanism of flexible raft-piles in layered soils under repeated loading

作　　者：黄茂松[1,2] 李波[3] 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]长江科学院水利部岩土力学与工程重点实验室,武汉430010

出　　处：《岩土力学》2012年第8期2388-2394,共7页Rock and Soil Mechanics

基　　金：国家高技术研究发展计划(No.2007AA11Z117)

摘　　要：提出一种层状地基中柔性筏板-群桩共同作用分析方法,探讨筏板刚度对桩筏基础沉降的影响,并成功预测了往复荷载下桩筏基础的长期沉降。筏板刚度采用Mindlin板理论的有限单元法分析;桩-土体系的刚度矩阵中,桩顶面-桩顶面、桩顶面-土表面以及土表面-土表面的相互作用分析采用层状剪切位移法借助层状地基的Burmister位移解求得。基于层状地基中柔性筏板-群桩的沉降计算方法以及往复荷载下土体压缩模量的衰减特性得到了桩筏基础的长期沉降预测方法。与已有文献方法和离心模型试验结果的对比分析表明,柔性筏板-群桩共同作用方法得到的沉降值具有较高的精度。A simplified analytical approach is proposed to study the behavior of the piled raft foundation with flexible raft in layered soils. It is focused on the effect of the stiffiness of the raft on the settlement of the piled raft foundation and the prediction of the long-term settlement of the piled raft foundation. The stiffness matrix of the raft is derived using the finite element method of Mindlin plate theory. The stiffness matrix includes the interaction effect of pile-pile, pile-soil and soil-soil, which are calculated through shear displacement method in layered soil and Burmister settlement solution. The long-term settlement of the piled raft foundation is deduced on the basis of the settlement of the piled raft foundation with the flexible raft in layered soils and the decay of the compression modulus because of the repeated loading. Comparison between the results of the existing analytical methods and the centrifuge tests shows the feasibility of the present method for analyzing the interaction of mechanism of flexible raft-piles.

关 键 词：层状地基 柔性筏板-群桩 共同作用 往复荷载 

分 类 号：TU473[建筑科学—结构工程]