Study On Surface Subsidence Caused By Tunneling Construction And The Existing Tunnel Station

With the increasing of the city’s subway, the network based subway systemare unavoidable, there are more and more crossing constructions. In crossing construction, thenew tunnels cast great effects on surface subsidence, but because the existing tunnel, therelations of interaction among the new tunnels, the existing tunnel and the stratum is verycomplicated, so the surface subsidence retroacted by the existing tunnel is different from thefree stratum. It is significance for predicting the surface subsidence of the crossingconstructions.This paper based on the Wuhan M6tunnel which pass through the existingChangqinghuayuan station of M2, theoretical analysis, field monitoring and numericalsimulation methods are used to analysis the surface subsidence retroacted by the existingtunnel, the main conclusion is as following:（1） Connecting with the practical situation, and simplifying it, it can figure out thevertical displacements based on the approximate solution of surface settlement proposed byVerruijt and Booker without any influence on the precision of results,and results has shownthat the existing tunnel stiffness and supporting intensity has great influence on surfacesubsidence.（2） Through the precision level to get actual deformation data of the surfacesubsidence.（3） Using FLAC3D simulate the excavation with different cases, analyzes thesettlement regularities, the results have shown that the station stiffness and tunnel supporthave a great influence on surface subsidence, and the effect scope by the existing tunnelstation are limited to the spans of tunnel station and a small area around the station because ofthe station is ultra shallow buried station.