中文摘要：

为得到在开挖过程中围护桩受到的弯矩和侧向位移随开挖深度变化的规律，对比分析不同断面在开挖中板下土体过程中加撑与不加撑对围护桩内力和位移的影响，采用了GTS软件对中街车站PBA法开挖中板下土体进行二维分析，确定了钢支撑的间距和位置，得出了加撑后围护桩所受的最大弯矩及侧向位移都有较大幅度的减小的结论，其中最大弯矩能减少27．8％，侧向偏移最多能减少31．7％。

英文摘要：

In order to get the moment of retaining pile during the excavation and the regulation of lateral displacement changing with excavation depth, comparative analysis was made on the internal force and displacement of retaining pile both with and without steel support during the excavation in different crossing-sections. Two-dimenslonal analysis was made on the excavation soll in Zhongjie Station with PBA method by MIDAS - GTS to determined the location and the spacing of the steel support and the conclusion was got that the largest moment of piles and the displacement would be reduced 27.8% and 31.7% respectively with steel support.