逆作法基坑围护的变形及邻近建筑沉降实测分析

通过对上海兴业大厦深基坑工程在施工过程中引起的围护变形及邻近建筑物沉降实测分析 ,发现逆作法基坑楼板支撑体系具有很强的抗变形能力 ;而且地下一层楼板形成之后 ,邻近建筑物沉降已基本稳定 ,故能很好满足软土地区基坑开挖变形要求。发现邻近建筑物沉降中有相当部分产生于地下连续墙成槽阶段 ,所以特别强调先于地下连续墙成槽施工树根桩及深层搅拌桩等隔离措施的必要性。此外还讨论了邻近建筑物沉降受自身基础类型的影响以及施工局部超载可能引起围护结构不利变形等问题

Analysis on Deformation of Foundation Pit Enclosure and Settlement of Neighboring Building in Case of Top-Down Technology

Based on analysis of deformation of enclosu re and settlement of neigh boring building during construction of deep foundation pit of Xinye Building, Sh anghai, it is found that the supporting system of floor of foundation pit with t op-down technology has the ability against deformation. After formation of floo r in underground first story, the settlement of the neighboring building tends to be stable, which can meet the requirement on deformation of foundation pit duri ng excavation in soft soil region. It is found that a great part of settlement o f neighboring building was formed during trench cutting for the underground cont inuous wall, so it is necessary to have isolation measure before trenching of un derground continuous wall, such as deep mixing pile. In addition, the influence of neighboring building's foundation on its settlement as well as the deformatio n of enclosure caused by partial overloading during construction is discussed.