堆载作用下地下连续墙-桩组合基础数值分析

Numerical Analysis of Diaphragm Wall-Piles Composite Foundation under Lateral loading

地下连续墙-桩组合基础的理论研究尚处于起步阶段,地下连续墙-桩组合基础和周围土体共同作用时其水平变形和内力变化机理以及载荷之间的分担情况已成为亟待解决的关键问题。基于堆载作用下地下连续墙-桩组合基础的水平承载性状,采用有限差分软件FLAC3D进行数值分析,探讨不同堆载等级、不同墙桩长度比、有无竖向荷载、桩径、堆载面积以及堆载距离等影响因素对地下连续墙-桩组合基础的水平变形及的变化规律。结果表明:堆载等级、不同墙桩长度比、堆载距离以及堆载面积对组合基础的水平变形和内力的影响敏感性较为突出;组合基础上部和地下连续墙与桩的连接处2个部位需要着重考虑不利影响问题;组合基础上部的地下连续墙对水平推力的承担比重较大,下部的桩主要起嵌固作用,地下连续墙与桩的长度比为4∶6时设计更合理。

The study of the theory of diaphragm wallspiles composite foundation is still in its infancy.With the interaction between the composite foundation and the soil,the problems of study internal force and deformation regulation of composite foundation and load sharing ratio are urgent to be solved.The FLAC3D software is adopted to simulate based on lateral response of the composite foundation.The different surcharge,the diaphragm walls piles length ratio,vertical loads,different pile diameter,the area of surcharge load and the distance of surcharge load are analyzed and discussed to study internal force and deformation regulation.The results showed that:The parameters of the different surcharge,the diaphragm walls piles length ratio the area of surcharge load and the distance of surcharge load are relatively sensitive.There are two parts of the combined foundation to consider the adverse effects.The load on supporting the horizontal thrust is mainly resisted by diaphragm walls and the bearing force of piles is small,the length of the diaphragm wallpiles design more reasonable when the ratio of4:6.