Comparative analysis of ground settlement caused by two kinds of tunnel excavation method

摘要

By Inverse analysis through the actual monitoring data and laboratory test, get physical and mechanical parameters of rock and soil mass, use the numerical simulation method to simulate the surface subsidence process of Qingdao city tunnel ZK1 + 810 ～ ZK2 + 810 interval caused by two tunnel excavation methods (the actual use of up and down the steps method and the planned use of the advancing drift whole section method) and comparatively analysis surface subsidence caused by the two methods of construction. The research results show that the surface subsidence causes by the two kinds of construction technology are experienced four stages, namely the impact in advance stage of rapid growth stage, slow growth stage, subsidence and subsidence stabilization stage; The maximum value of surface subsidence caused by up and down the steps method of excavation is greater than that of the advancing drift whole section method; transverse range of ground surface settlement induced by step excavation is about 2D from both sides of the center line of the tunnel, the horizontal range of surface subsidence in advancing drift under construction is generally about 1.5 D ～ 2 D; longitudinal range of the surface subsidence caused by advancing drift under the construction is smaller than method of up and down the steps. The conclusion provides the technical support for the tunnel design and construction.