软土地区地铁车站深基坑开挖中框架逆作法的设计与应用

Application of Frame-top-down Construction in Deep Excavation of Subway Station in Soft Clay

综合明挖顺作法开挖速度快、楼板逆作法刚度大的优点,运用明挖与逆作相结合的框架逆作法,在深基坑关键部位以楼板的框架体系代替支撑,在留出大量出土空间的同时,支撑体系的整体刚度得以加强,从而充分利用"时空效应"原理,加快土体开挖和支撑安装速度,达到控制基坑变形、保护基坑周边环境的目的。

The frame-top-down construction method is put forward, which combines the quick-construction feature of open excavation and the rigid-stiffness feature of top down excavation. The brace is replaced by the frame at the pivotal place of the deep pit,the large area for excavation is remained, and the stiffness of the brace system is improved. So, the time-space effect method is applied to accelerate the excavation and brace making and control the pit deformation and protect the environment.