超大面积深基坑逆作法施工技术的探讨

针对上海铁路枢纽南站北广场基坑工程,在采用主体结构与支护结构相结合的逆作法施工过程中,对超大面积深基坑采取了一柱一桩垂直度控制、降微承压水、大开口、盆式和分块平衡对称抽条开挖以及节点处理等措施,解决了超大面积深基坑逆作法施工的一些关键施工技术.

Discussion on the Construction Techniques of Oversized Excavation Pit Constructed by Top- down Method

The foundation pit of the North Square of Shanghai South Railway Station was constructed by top-down method. During the construction process of this oversized excavation pit, many countermeasures were adopted. These measures included the control method of perpendicularity of the single lattice column over single pile; dewatering measurement, setting big holes in the slab for the convenience of conveying soil, rational planning of soil excavation, and treatment of some joints. Some key construction techniques were also pointed out for the excavation pit constructed by top-down method.