基于强度折减法的地铁车站交叉段稳定性分析

基于有限元强度折减原理,分别以特征点位移突变、等效塑形应变贯通和计算收敛等方法作为地铁车站隧道交叉段整体稳定性分析的失稳破坏判据,进行整体安全系数计算,通过实例分析,提出适合地铁车站隧道交叉段整体稳定性分析的强度折减判据。研究结果表明:有限元强度折减法可以定量地得出地铁车站隧道交叉段的整体安全系数;收敛判据计算得出的安全系数明显大于其他两种判据的结果,单独使用任何一种判据都不能真实地确定安全系数;采用特征点位移突变与等效塑形应变贯通两者相结合的综合判据可以较好的得到地铁车站隧道交叉段的整体安全系数。

Stability Analysis of Subway Station Intersections

In order to discuss the calculation method on general safety factor and analyze strength reduction criterion which is more suitable for the general stability analysis of subway station tunnel intersections, the general stability of subway station tunnel intersections are analyzed, which is based on strength reduction finite element method, with three methods for the criterion of abrupt change of the relationship between the displacement, plastic strain zone connection criterion and the reduction coefficient at a certain characteristic location and the divergence criterion of numerical calculation as a failure criterion. The results show that the strength reduction finite element method can be quantitatively obtained general safety coefficient of subway station tunnel intersections. The safety coefficient are calaulated by the divergence criterion of numerical calculation significantly greater than the other two. Using any one of criteria in stability analysis of subway station tunnel intersections cannot get the real safety factor, while using plastic strain zone connection criterion combining with the criterion of abrupt changing displacement of characteristics point,as a comprehensive criterion can be good for achieving the safety factor of subway station tunnel intersections.