临河软土地层深基坑施工地连墙变形规律研究

Study on deformation law of connecting wall at construction site of deep foundation pit in soft soil layer close to rivers

当前全国各大城市交通市政工程建设开始迈向地铁时代,地铁建设既能解决城市交通紧张问题,又不占用建设用地和耕地,但建设地铁时确保深基坑施工安全及控制基坑变形是工作重点,以杭州至德清市域铁路工程1标总承包二工区区间风井深基坑工程为背景,对临河软土地质条件下深基坑施工地连墙变形的规律展开了研究,得到以下主要研究成果:临河软土地区地连墙水平位移变形规律为“弓形”,其变形量随深基坑施工进度逐渐增加,最大偏移量发生在第四道支撑和第五道支撑之间;地连墙顶部的变形量随基坑施工也不断增加,靠近基坑长边中部位置的竖向位移处于波动型缓慢增长趋势,同时墙顶水平位移也以波动型缓慢增长为主;地连墙的变形控制措施主要可以从优化支撑布设间距、调整地连墙入土深度和优化基坑开挖顺序等方面进行控制。

At present,transportation and municipal engineering construction in major cities across the country has begun to step into the subway era.Subway construction can not only solve the problem of urban traffic tension,but also does not occupy construction land and cultivated land,but ensuring the construction safety of deep foundation pit and controlling the deformation of foundation pit are the key tasks during subway construction.This paper takes the wind shaft deep foundation pit project in the second section of the 1st standard general contract of the railway project from Hangzhou to Deqing City as the background.The main results are as follows:The horizontal displacement deformation law of the ground wall in the soft soil area of the river is“bow”,the deformation increases gradually with the construction progress of the deep foundation pit,and the maximum deviation occurs between the fourth and fifth supports;The deformation of the top of the ground wall also increases with the foundation pit construction,and the vertical displacement near the middle of the long side of the foundation pit is in a slow growth trend of fluctuation,while the horizontal displacement of the top of the wall is mainly in a slow growth trend of fluctuation;The deformation control measures of the ground connecting wall can be mainly controlled from the aspects of optimizing the support layout spacing,adjusting the depth of the ground connecting wall and optimizing the excavation sequence of the foundation pit.