错层式软土基坑的大变形实例分析

Case analysis of large deformation for staggered pit in soft soil foundation

地下室错层布置往往导致形成分级基坑,对于分级支护的变形及作用机理还需要进一步研究。本文针对某软土地基的错层基坑大变形原因进行了深入分析,并结合有限元整体模拟对比了地下二层基坑开挖对地下一层的巨大影响,分析结果表明地下二层基坑开挖后支护结构和土体变形大幅增长,因此对于错层基坑,应进行整体变形分析,采用分离式设计并不安全,建议地下室错层距离保持在5倍基坑开挖深度以上。

The staggered layout of basements often leads to the formation of graded foundation pits,and further research is needed on the deformation and mechanism of graded support.This paper analyses deeply the large deformation of a staggered pit in the soft soil foundation.And,the finite element model is used to comparing the huge impact of the excavation of the underground second floor pit to the underground first floor pit.The analysis results show that the support structure and the soil deformation increase significantly after the excavation of the underground second floor pit.Therefore,an overall deformation analysis should be conducted for the staggered foundation pits,and the separate design between t staggered pits is not safe.The conclusion is that the staggered distance of the basement should be maintained at 5 times or more of the excavation depth of the foundation pit.