大口径排水管道沟槽基坑开挖对既有轨道交通隧道结构影响分析

Analysis on Influence of Excavation of Large-Diameter Drainage Channel Trench Foundation Pit on Existing Tunnel

城市建成区亟需敷设大口径排水管道以解决区域系统排水瓶颈,然而城市中心城区既有轨道交通隧道结构呈几何级数增加,形成一对矛盾。以上海复兴中路(重庆南路—西藏南路)道路积水改善工程为例,通过工程的数值模拟分析,研究大口径排水管道沟槽基坑开挖对既有轨道交通隧道结构影响。数值模拟分析结果表明,在工程最不利工况下,敷设管道对轨道交通L10影响有限,轨道交通隧道最大竖向位移量为5 mm,能够满足轨道交通结构允许位移量(20 mm)的要求。分析结果为工程顺利推进起到强有力的技术支撑。

Urban built-up areas need to lay large-diameter drainage pipes to solve drainage bottlenecks of the regional system urgently. However, the existing urban rail transit tunnels structures in the downtown increases in geometric series. The current situation is forming a pair of contradictions. Taking the road water improvement project of Shanghai Middle Fuxing Rd.( from Chongqing South Rd. to South Xi'zang Rd.) for example, the influence of trench excavation of large-diameter drainage pipe on the structure of existing rail transit tunnel is studied by numerical simulation. Under the most unfavorable operating conditions, the numerical simulation results show that the maximum vertical displacement of the rail transit tunnel is 5 mm, which can meet the requirements of the permissible displacement of the rail transit structure requirements(20 mm). The analysis results can play a strong technical support for the smooth progress of the project.