某深基坑安全开挖引起临近建筑物较大沉降的实例分析

Case study of settlement of adjacent buildings caused by excavation of a deep foundation pit

在基坑开挖过程中确保周边建筑物的变形和沉降在安全范围是基坑支护体系的重要使命。结合一开挖深度约12.6 m深基坑施工过程中的现场监测结果,分析了深基坑开挖导致临近建筑物沉降变形的发展过程,及其与地质条件、基坑开挖施工工序、支护结构水平位移、邻近建筑物的基础型式之间的关系。结果表明,支护桩间水土流失及不当的施工工序是诱发临近浅基础建筑沉降过大的根本原因。强大的支护体系、有效的止水帷幕和正确的施工工序是控制该类深基坑开挖工程对邻近建筑物影响的关键。

During the excavation process of foundation pits, it is an important mission for the supporting system to ensure the deformation and settlement of the surrounding buildings. Based on the field monitoring results of a deep foundation pit with excavation depth of about 12.6 m during construction process, the development process of the induced settlement and deformation of the adjacent buildings is analyzed as well as its relationship with the geological conditions, excavation construction sequence, horizontal displacement of supporting structures and the basic types of neighboring buildings. The results show that the soil loss between supporting piles and improper construction sequence are the basic reason for large settlement of the adjacent buildings with shallow foundations. Powerful supporting system, effective water curtain and correct construction sequence are the key to control the influence of deep excavation on the adjacent buildings.