毛竹复合土钉墙数值分析

本文采用非线性有限元法探讨软土深基坑毛竹复合土钉墙支护机理。数值模拟采用ABAQUS三维非线性有限元软件和实体单元(取代传统的结构单元)来模拟毛竹土钉与土体的相互作用,土体采用莫尔-库仑理想弹塑性模型,基坑的变形分析采用在此软件平台上二次开发能反映基坑开挖卸载的邓肯-张E-B模型,模型参数采用三轴加、卸载应力路径试验值或经验值。毛竹土钉按张拉破坏的弹性材料进行模拟,坡脚毛竹排桩等效为连续板桩来模拟。数值模拟预测结果与现场实测结果吻合较好,表明三维非线性有限元法对毛竹复合土钉墙的变形预测具有定量计算精度,可用于动态指导基坑开挖、支护设计和施工。

Numerical Analysis of Bamboo Composite Soil Nailing Wall

Based on the nonlinear finite element method （FE）, supporting mechanism of bamboo composite soil nailing wall at soft soil deep foundation pit was investigated .Three-dimensional nonlinear finite element software of ABAQUS was used for numerical simulation , and entity unit （ units） was used to replace the traditional structure to simulate the bamboo soil nail and soil interaction .The Mohr-Cou-lomb＇s ideal elastic-plastic model was used for soil , secondary developed Duncan -Chang E-B model which can reflect the excavation unloading and based on the software platform was used to analyze foundation pit deformation, and test or experience values of three axis un-loading stress path testing were accepted as model parameters .Bamboo soil nails were simulated according to the elastic material tension damage, and the slope foot bamboo pile was simulated equivalent to continuous sheet pile .Numerical simulation prediction results are a-greement with the measured results , show that the three -dimensional nonlinear finite element method （ fem） of bamboo composite soil nailing wall deformation prediction has quantitative calculation accuracy , can be used to guide the design and construction of excavation and supporting .