两种浅埋暗挖法开挖地铁车站的比较

Comparative Analysis of Two Different Excavation Methods of Subway Station

在地下结构中,开挖方式对地表沉降和结构稳定影响很大.为了选取更合适的开挖方式,采用有限差分程序FLAC对某地的一个地铁车站的两种开挖过程设计方案进行了模拟,分析了开挖后土体和支护的受力情况,发现导洞开挖后,在顶板和底板处产生较大范围的卸载区;轴力和弯矩的最大值在拱角或底板的中间;两种开挖方式产生的位移基本相同.

In underground structure, excavation method has a great impact on land subsidence and structure stability. In order to choose a more appropriate excavation method, the finite difference procedure FLAC is adopted to simulate the two different excavation process design schemes of a subway station somewhere. The dynamic change of stress in soil and forces in support structure is analyzed. It is found that after the excavation of the adit, a large depressed zone will form in both the roof and the floor. The displacement induced by the adit accounts for almost 60% of the total displacement. The maximum axial force and moment in the support structure occur in the middle of floor or at the conjunction of arch and sidewall. The displacement of the two excavation methods is quite similar. These conclusions provide important reference for the design and construction for the station.