弹性地基梁杆系有限元法在深大基坑工程支护设计中的应用

由于弹性地基梁法能够反映支挡结构与土的相互作用,并可有效考虑基坑开挖、回填过程中各种基本因素和复杂情况对支护结构内力和变形的影响,本文根据Winkler弹性地基梁的计算原理和方法,编制了弹性杆系有限元计算程序,对深圳市民广场深大基坑桩锚支护结构进行了设计计算,获得了支护桩桩身位移和弯矩随开挖过程的分布变化规律,计算结果有效指导和优化了基坑支护设计,保证了基坑和邻近基坑的地铁区间隧道结构的安全,支护设计取得了显著的经济效益。

Application of bar system FEM for beam on elastic foundation in supporting design for a deep and large foundation pit engineering

The interaction between supporting structure of soldier pile and soil mass can be reflected by the principle of beam on elastic foundation, and at the same time, it can effectively take into consideration the influences of various factors and complex situation during the course of excavation and backfill for foundation pit on internal force and deformation of soldier pile. So according to the computation principle and method of Winkler beam on elastic foundation, a computing program of elastic bar system FEM has been programmed. The program has been applied to compute the internal force and deformation of anchored soldier piles in a deep and large foundation pit of Shenzhen People′s Square. The variation law of displacement and bending moment of supporting soldier pile during excavation has been obtained. The computed results have efficiently guided and optimized supporting design,and have guaranteed safety for the deep foundation pit and Shenzhen metro structure which is close to the foundation pit. Thus remarkable economic results have been achieved.