连接邻近构筑物的基坑桩锚支护系统应力应变特征分析

Stress-strain Characteristics of Pile Anchor Supporting System Connected with Adjacent Underground Structure

城区用地紧张导致基坑支护结构与周围建筑结构形成整体的支护体系将会成为未来基坑工程不可避免的模式。掌握与邻近地下结构连接的基坑支护系统应力应变规律、破坏模式对指导工程实践具有十分重要的意义。运用数值法和快速拉格朗日差分法研究与邻近地下结构物连接的桩锚支护系统的应力应变规律。研究表明:支护系统与地下车库连接后,支护结构及地下车库部分均发生应力集中;当基坑周围存在地下结构物时,将结构物靠近基坑一侧土体全部清除会使基坑侧壁变形减小,但会增加地下结构物受力变形,地下车库侧墙与底板交接处变形最大,支柱位置受力最大。当邻近地下结构物强度较低时可保留基坑侧壁与结构物之间的土体,以缓冲应力传递,在一定程度上保证地下结构物安全。

The supporting structure of the foundation pit and surrounding building structure form an integral supporting system,which will become the inevitable mode of foundation pit engineering in the future due to the urban land tension in urban areas.It is of great significance to master the stress-strain law and damage mode of the foundation pit supporting system connected with the adjacent underground structure to guide the engineering practice.The stress-strain rule of the pile-anchor support system connected to adjacent underground structures is analyzed by the numerical method and the Fast Lagrangian Analysis of Continua.The study shows that after the support system and the underground garage,the supporting structure and the underground garage are concentrated;when the underground structure exists around the foundation pit,the removal of the soil near the foundation pit will reduce the sidewall of the foundation pit,but increase the force deformation of the underground structure.The junction between the sidewall and the underground garage has the maximum deformation,and the pillar position has the maximum force.When the strength of the adjacent underground structures is low,the soil between the foundation pit sidewall and the structure can be retained to buffer the stress transmission and ensure the safety of the underground structures to a certain extent.