关于基坑对市域铁路影响的防护控制分析

Analysis on the Protection Control of the Influence of Foundation Pit on Urban Railway

基坑施工期间如何对临近市域铁路桥墩进行保护是一个十分重要的问题。论文以温州市龙湾区瑶溪北单元11-A-24地块基坑开挖对临近温州市域铁路S1线桥墩的影响为背景,阐述了多项减小基坑施工过程中对周边市域铁路位移影响的措施:1)设计上采用双排钻孔灌注桩、水泥搅拌桩与地下室顶部连接的钢筋混凝土水平支撑梁等多项保护措施;2)施工中遵循"大基坑,小开挖"及"分层、分块开挖"的原则;3)加强对桥梁的水平及竖向位移进行监测控制。最后通过理论计算及软件模拟,结果显示基坑开挖过程中S1线桥墩水平位移最大处为7.56 mm,沉降位移最大处为4.63 mm,未超过规范限制。

It is a very important issue that how to protect the adjacent urban railway bridge pier during construction of the foundation pit.Based on the influence of foundation pit excavation of Block 11-A-24 in Yaoxi North Unit,Longwan District,Wenzhou City on the adjacent piers of Wenzhou Railway(S1 line),this paper expounds several measures to reduce the influence of foundation pit construction on the displacement of surrounding city railway:(1)several protective measures such as double row bored piles,cement mixing piles and the reinforced concrete horizontal bracing beam connection with the top of basement are adopted in design;(2)follow the principle of“large foundation pit,small excavation”and“layered and block excavation”;(3)strengthen the monitoring and control of the horizontal and vertical displacement of the bridge.Finally,through theoretical calculation and software simulation,the results show that the maximum horizontal displacement and maximum settlement of S1 line pier are 7.56 mm and 4.63 mm respectively,which are within the allowable scope of the code.