考虑K_0固结或渗流与变形耦合的软土基坑工程二维数值模拟  

2D numerical simulation of considering K_0 consolidation and coupling of deformation and seepage in soft soil excavation engineering

作　　者：陈林靖[1] 戴自航[1] 刘志伟[2] 

机构地区：[1]福州大学岩土工程研究所,福建福州350108 [2]福建省电力公司,福建福州350003

出　　处：《铁道科学与工程学报》2011年第1期39-47,共9页Journal of Railway Science and Engineering

基　　金：福建省自然科学基金重点资助项目(D0720001);福州大学科研启动基金资助项目(022279)

摘　　要：在大型有限元通用软件ABAQUS的平台上进行了邓肯-张模型用户材料子程序的开发,首先采用平面应变单元、二维梁单元和二维桁架单元考虑接触相互作用的耦合有限元法,对福州市一典型软土基坑工程按实际分步开挖和支护过程进行了二维数值模拟"目标试验"。模拟过程中土体分别采用了K0固结和正常固结试样的邓肯-张模型及莫尔-库仑理想弹塑性模型,将各模型预测值与现场实际监测结果和现行规范建议的m法设计计算结果进行了比较。结果表明:以K0固结试样CU试验得到的邓肯-张模型参数进行总应力分析的预测结果与实测结果最为接近。其次,由K0固结试样CD试验得到的邓肯-张模型参数,采用渗流和变形耦合的有效应力分析有限元法,探讨了稳定渗流作用下基坑工程的数值模拟方法,揭示了基坑施工过程中总孔隙水压力和超静孔隙水压力的变化规律,供工程实践参考。The Duncan-Chang constitutive model was developed by using user subroutine in ABAQUS which is a general-purpose finite element analysis software.According to the foundation pit engineering example with soft soils in Fuzhou city,the actual construction processes of the excavating and retaining structures were simulated by 2D nonlinear finite element numerical simulation ＂object tests＂ with plane strain elements,two dimensional beam elements and two dimensional truss elements using coupling finite element method which considers contact interactions.The K0 consolidation and normal consolidation samples with the Duncan-Chang＇s model and Mohr-Coulomb＇s ideal elastic-plasticity model were adopted.The estimated results of each model were compared with the field measurements and the calculation with m method which the current technical code suggests.The comparisons indicate that the total stress analysis results using the Duncan-Chang constitutive model parameters abtained by K0 consolidation samples with CU tests are closest to the field measurements.Then the regularity for change of pore water pressure and excess pore water pressure are drawn by the effective stress analysis finite element method considering coupling deformation and seepage under steady seepage flow using K0 consolidation samples with CD tests for engineering practice reference.

关 键 词：K0固结 渗流耦合效应 邓肯-张模型 总应力分析 有效应力分析 

分 类 号：TU476[建筑科学—结构工程]