逐层开挖对支护结构体系工作性状影响数值分析方法研究

基于有限元数值分析方法,建立了遵循时空效应的逐层开挖、随挖随撑的分步施工模拟方法。该方法提出考虑边界效应、开挖渗流和挡墙埋深等因素的软土地基深基坑计算区域综合确定法,引入表征土体应力应变非线性关系的H-S强化土体模型,设计反映土工结构体和施工荷载变化的基坑开挖基本工况和支撑预应力施加方案,形成支撑预应力取值迭代修正法,解决了原型选择、模拟方法、模拟工况关键技术问题。分析结果能够反映基坑逐层开挖过程土工结构体和施工荷载的逐渐变化与相互影响。

Numerical analysis method of the effect modeling on supporting structures performances due to excavating layer by layer

A numerical analysis method based on finite element method(FEM) was proposed to simulate the staged construction process,following the rule of excavating layer by layer.The key techniques in establishing the method,including selection of simulated archetype,simulating methods,and processes design,were discussed through proposing an integrated method in estimating calculating range of the model and an alternating method in evaluating the strut prestresses,introducing the Hardening-Soil(H-S) model,respectively designing the basic construction process and scheme of strut prestressing,both considering the changes of geo-structure and construction load.The results of the numerical analysis reflect the gradually varieties in the earth-structure association and construction load and their inter-influence.