Study on Reasonable Excavation Step of Closely Foundation Excavation on Both Sides of Existing Metro Tunnel
Chigang Station of Guangzhou Metro Line 12 is penetrated by the existing tunnel of Line 8.The foundation excavation of the stations on both sides of the existing line are closely attached to the tunnel,and the tunnel is not out of service during the construction.The excavation has a significant impact on the existing operating tunnel.Due to the actual factors,the excavation of both sides of the foundation excavation is not synchronized,and the influence on the deformation of the foundation excavation and tunnel is unknown.Therefore,through the numerical calculation method,the influence of unsynchronous excavation on the foundation excavation and the tunnel deformation of the excavation on both sides of the closely attached metro tunnel is explored,and the reasonable excavation step sequence is proposed.The results show that with the increase of the leading excavation step of one side of the foundation excavation,the maximum lateral displacement of the surrounding tunnel during the excavation process increases,and the lateral displacement of the tunnel to this side increases.The surface subsidence above the tunnel is W shaped.The reasonable step difference takes the horizontal displacement of the tunnel as the main control index,and the construction does not exceed the warning value when the two sides are excavated at the same time or the No.1 foundation excavation is one or two steps ahead,so it is a reasonable step difference.
万方数据
维普
