上海地区浅大基坑的事故原因及对策

The Cause and Countermeasures for Accident at Shallow and Big Foundation Pit in Shanghai

上海地区面积较大的浅基坑支护设计时,一般采用土钉墙,水泥土搅拌桩重力坝,SMW工法+锚杆等围护形式。实践证明,悬臂结构支护的浅大基坑开挖过程中变形较大,会出现地面下沉,建筑物倾斜,外墙开裂等现象,更容易发生工程事故。作者以上海地区为例,总结自己多年的基坑设计和咨询经验,针对不同工程实例提出了规模较大的浅基坑容易出现的问题,分析了的一些事故原因,并从围护设计、施工、监测等方面提出相应预防和处理措施。

Shallow and big foundation pits in Shanghai are commonly supported with soil nail walls,cement-soil deep mixing pile or SMW＋anchor.Practice shows that the accidents occurred more easily at shallow and big foundation pit with cantilever structure.Taking the Shanghai area for example,the problems about shallow and big foundation pit were summed up based on author＇s experience on group design and consultation for many years.And some reasons of accident was analyzed,then,the prevention and cure measures were put forward from the aspects of enclosure design,construction,monitoring.