相邻地铁轨道共墙同时非同步深基坑施工方案合理性探讨

Discussion on Rationality of Non-synchronous Deep Foundation Excavation Construction Scheme in Adjacent Metro Track Share one Wall

目前国内学者对临近地铁轨道的建筑深基坑施工过程对围护结构和地铁车站或隧道的变形规律开展了较丰富的研究工作,而鲜见对建筑深基坑与紧邻的地铁车站基坑同时非同步逆作法施工方案合理性的探讨。本文依托合肥市新交通大厦深基坑与地铁轨道1、2号线共用地下连续墙的工程特征,提出了一种相邻地铁轨道共墙同时非同步深基坑逆作法施工方案,采用有限差分软件对新交通大厦深基坑与地铁轨道1、2号线基坑同时非同步逆作法施工过程进行数值模拟。数值计算分析结果显示:在新交通大厦深基坑和地铁1、2号线基坑同时非同步施工过程中,共用地下连续墙水平位移逐渐增大,水平位移最大值为3.9mm,在规范要求的25mm范围内;基坑土体应力释放传递路径在施工过程中发生不断的调整,使地下连续墙两侧土体隆起值增大,基坑隆起最大值为9.0mm,小于监测警戒值30mm。计算分析结果表明,本文提出的相邻地铁轨道共墙同时非同步深基坑逆作法施工方案是合理可行的。

The domestic scholars have done a lot of research work on the deformation regularity of enclosure structure and subway station or tunnel during the excavation process of the deep foundation excavation,it is rare to discuss the rationality of the simultaneous asynchronous construction method for the deep foundation excavation and the adjacent subway foundation excavation. Based on the characteristics of the deep foundation excavation of New Traffic Building and the adjacent subway foundation excavation share of the underground continuous wall,the simultaneous asynchronous construction scheme of deep foundation excavation and adjacent subway foundation excavation is proposed,the finite element software is used to simulate the simultaneous asynchronous excavation process of the deep foundation excavation of New Traffic Building and the adjacent subway foundation excavation. The calculated result showed that the horizontal deformation of diaphragm wall shared with metro station become larger during the excavation,the maximum horizontal displacement is 3. 9 mm,within the specification requirements 25 mm. The stress release and transfer path of soil is constantly adjusted during the excavation process,the uplift value of the soil on both sides of the diaphragm wall get increased,the maximum uplift value of deep foundation excavation is 9. 0 mm,less than the monitoring warning value 30 mm. According to the above numerical simulation results,it can be explained that the simultaneous asynchronous construction scheme of deep foundation excavation and adjacent subway foundation excavation is feasible and reasonable.