采用钻孔灌注桩加水泥土搅拌柱作围护,以一道角撑加对撑作支撑,辅以二次开挖和坑底压密注浆等措施.解决了21000m~2特大面积深基坑的支护和挖土问题. The use of bored piles and cement-soil mixing columns as enclosure, with a gusset and support for supporting, supplemented by secondary excavation and pit bottom compaction grouting and other measures to solve the 21000m~2 extra large area of ​​the deep pit Support and digging problems.