The Surface Deformation Law with Engineering Mechanics Caused by Construction of Tunnels with Large Section and Small Interval

There is a large section tunnel and neighboring tunnels in parallel with cross diaphragm method (CRD) and single excavation by drilling-blasting method at a subway station in Dalian. For the construction of shallow buried tunnels, this article has carried on the numerical simulation analysis of dynamic excavation in order to draw a law of surface deformation due to the interaction effect of CRD and drilling and blasting method by analyzing the surface subsidence in every sequential step. It is concluded that maximum ground settlement point affected by different construction stage and the influence of excavation caused by stress redistribution will keep away from or be close to the large cross section tunnel axis as the reference line whose maximum deviation value is the clear distance of 0.6 times; In different construction stages, the settlement decreases along with the increase of distance far away the maximum ground settlement point; Adjacent tunnel construction has a significant effect on the surface deformation.