碎石桩复合地基大变形非线性固结模型  

Nonlinear consolidation model of stone column composite foundation considering large strain

作　　者：周亚东[1,2] 翟鑫东 李顺群 陈思源[1] ZHOU Ya-dong;ZHAI Xin-dong;LI Shun-qun;CHEN Si-yuan(Key Laboratory of Soft Soils and Engineering Environment of Tianjin Province,Tianjin Chengjian University,Tianjin 300384,China;College of Civil Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]天津城建大学天津市软土特性与工程环境重点实验室,天津300384 [2]同济大学土木工程学院,上海200092

出　　处：《岩土力学》2022年第10期2777-2784,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51608351);天津市自然科学基金(No.18JCZDJC10010);天津市科技支撑重点项目(No.19YFZCSF00820)。

摘　　要：基于分段线性差分法,建立了一种碎石桩复合地基大变形非线性固结模型SC1。该模型可以进行等应力和等应变条件下桩土复合地基固结分析,同时能够考虑涂抹区、井阻、桩土自重、变荷载,以及固结过程中桩土参数的非线性变化和大变形问题,并编制了Fortran计算程序。分别采用基于等应变假设的桩土复合地基解析解和室内试验数据验证了模型的正确性,小变形条件下,该模型数值解与有无井阻及涂抹区的桩土复合地基解析解均能较好吻合;大变形非线性条件下,模型计算结果与室内试验数据基本一致。采用该模型预测实际工程,随固结时间延长,模型等应力与等应变的沉降量计算值相差逐渐增大,现场实测值介于等应力和等应变条件下模型计算结果之间。Based on the piece-linear finite difference approach,a nonlinear consolidation model,called SC1,of stone column composite foundation considering large strain was developed.The model has the ability to analyze the consolidation of pile-soil composite foundation under the conditions of free stress and equal strain,and to consider well resistance,smear area,self-weight of pile-soil,variable load,as well as the nonlinear changes of pile-soil parameters in the consolidation process.The model was validated against the equal strain analytical solution and experiment.Under the condition of small strain,the numerical solutions of the model are in good agreement with the analytical solution of pile-soil composite foundation with or without well resistance and smear area.Under the conditions of large strain and nonlinear consolidation,the model calculation results are basically consistent with the experiment data.Then,the model was used to predict a practical engineering,and it was found that with the extension of consolidation time,the difference between the calculated values of the model based on free stress and equal strain increases gradually,and the field measured value is between the numerical solutions of the model with free stress and equal strain.

关 键 词：复合地基 碎石桩 大变形 非线性 固结模型 

分 类 号：TU473[建筑科学—结构工程]