超深地下连续墙成槽施工过程三维数值分析

Three-dimensional Numerical Simulation of the Trenching Construction of Ultra-deep Diaphragm Wall

天津地铁5、6号线宾馆西路地铁站地下连续墙施工区域周边建筑林立、管线密集,其成槽面临极大挑战。采用数值计算分析软件,选取典型的紧邻3幅地下连续墙对该地下连续墙成槽过程中的周边土地受力与变形机理进行探讨。计算结果表明,采用泥浆护壁进行超深地下连续墙成槽开挖时,超深地下连续墙侧向卸荷效应显著,且槽段周围土体的应力重分布明显;泥浆护壁阶段槽壁发生面向槽段内的侧向变形,同时在地面发生较大的沉降变形;混凝土浇筑后地面沉降变形会相应变小,但局部发生隆起,这主要源于侧向应力和槽壁反方向变形的作用。

The depth of diaphragm wall of Hotel Road subway station on Tianjin Metro Line 5 and 6 can up to55 m. The surrounding environment of the station contains many tall buildings and dense lines,thus great challenges are faced by the construction of diaphragm wall trenching. Three next typical diaphragm walls are selected to study force and deformation mechanism of the surrounding soil during trenching by using a numerical analysis software. The results show that there exists obvious lateral unloading effect in the trench face during deep diaphragm wall trenching construction,the stresses of the surrounding soil are greatly redistributed; Lateral deformation of trench will face to the inside groove segment and ground will have large settlement during slurry trenching stage; In the concreting stage,the trench face will produce anti-directional deformation and the ground settlement will be correspondingly reduced( locally even be uplifted) by the reason of lateral stress compensation.