土岩组合地层暗挖地铁车站参数优化研究

青岛地铁车站均为土、岩组合地层,车站大部分在风化程度不同的岩层中,因此研究土岩组合地层中暗挖法车站的合理埋深及结构参数有一定意义。以青岛地铁五四广场站为例,采用数值模拟方法,利用有限元软件Abaqus,结合强度折减法和结构安全系数方法,探讨暗挖车站稳定性的影响因素。通过对车站埋深、衬砌强度及应力释放率正交设计优化模拟,得出埋深影响车站围岩结构的稳定性最大,其次是衬砌强度和应力释放率。通过分析,对结构及施工参数进行了优化,优化方案的车站围岩安全系数为1.69,结构安全系数有足够的余度。

Study on Parameter Optimization of Tunneling around Subway Station in Stratum with Rock-soil

There are many differences in metros between those in Qingdao and most other domestic cities,the differences are mainly embodied in the different geological environment.Geological environment of most cities is soft soil or rock stratum of strong weathering,while strata in Qingdao are rock-soil combination.Study on rational depth and structure parameter of tunnelling method around subway station of different degree of weathering has certain significance.Based on May 4th Square Station project,Qingdao city,using numerical simulation method with finite elements software Abaqus combined with strength reduction and structure safety coefficient,to discuss the influence factors of stability of station.By specific analysis on simulations through orthogonal design about buried depth,lining strength and the stress release rate,the results obtained show that the largest factor is the buried depth,followed by lining strength and the minimum one is stress release rate.After analysing,the optimization of structure and construction parameters shows that at the rock safety coefficient of 1.69,the safety coefficient for the structure is redundant.