硬岩地区暗挖车站不同开挖方法对地表沉降影响的模拟研究

浅埋暗挖法施工必须结合当地地质情况选择合理的开挖方法,开挖过程中应严格控制相应变形,尽可能减小开挖扰动。以青岛地铁1号线某大跨度暗挖车站为工程背景,通过室内模型试验,采用全断面法、台阶法、双侧壁导坑法、CD(中隔壁)法、CRD(交叉中隔墙)法进行模拟隧道拱盖开挖试验,研究了各种施工方法下围岩压力的变化规律和沉降的变化趋势。模拟试验结果表明,在开挖过程中地表沉降及围岩变形可分为缓慢变形、快速沉降、稳定变形3个阶段。以全断面开挖法引起的最大沉降值为比较对象,其他施工方法在最大沉降值上均有一定程度的优化,其中CRD法的优化效果最显著。

Influence Simulation of Different Under-ground Excavation Methods on Surface Set-tlement for Underground Station Built in Hard Rock Area

The shallow tunneling construction method must select reasonable excavation according to the local geological conditions,in which the excavation disturbance and corresponding deformation must be reduced as much as possible.Taking the large-span underground excavation station of Qingdao Metro Line 1 as the engineering background,and through the indoor model,the simulation of tunnel arch cover excavation test with different construction methods,such as full section,step method,double side wall,center diagram(CD)and center cross diagram(CRD)is conducted,the variation law of surrounding rock pressure and the settlement deformation in various engineering methods are studied.The simulation results show that the surface settlement and surrounding rock deformation during excavation can be divided into three stages:slow settlement stage,rapid settlement stage and stable settlement stage.Taking the maximum settlement value as the comparative object which is caused by the full-section excavation method,other construction methods all have a certain degree of optimization in terms of the maximum settlement value,among which the CRD method has the most significant optimization effect.