昆明软土地区超大深基坑变形监测分析

Deformation Monitoring Analysis of Super-large Deep Foundation Excavation in Kunming Soft Soil Area

以昆明综合交通国际枢纽深大基坑为工程背景,分析昆明软土层中基坑周边环境的变形特性、立柱变形和支撑轴力变化情况。各测点的变形量均随开挖深度的增加而逐步增大,且基坑顶部变形最大,变形整体形态为“开口形”。地下连续墙变形随开挖深度的增加而增大,先缓慢增长,然后突然剧增。支撑与封板上车辆及料场荷载导致立柱竖向沉降。支撑最大轴力值与围护体侧向变形最大值分布形态基本匹配。各观测井水位变化幅度较小;基坑东侧靠近B塔楼区域存在漏水情况,水位变化幅度较大。随着各区域后续工况基坑逐步开挖,车站变形逐步增加,但变形较小,区间变形未发生较大变化。

Taking the deep and large foundation excavation of Kunming Comprehensive Transportation International Hub as the engineering background,the deformation characteristics,column deformation and support axial force changes of the surrounding environment of the construction foundation excavation in Kunming soft soil layer are analyzed.The deformation of each measuring point increases gradually with the increase of excavation depth,and the maximum deformation occurs at the top of the foundation excavation,and the overall deformation shape is“open”.The deformation of diaphragm wall increases with the increase of excavation depth.At first,the deformation increases slowly,and then suddenly increases sharply.The vertical settlement of the column is caused by supporting and sealing the load of vehicles on the board and the yard.The maximum axial force of the support is basically matched with the distribution pattern of the maximum lateral deformation of the enclosure.The variation range of water level in each observation well is small.There is water leakage in the area near tower B on the east side of the foundation excavation,and the water level changes greatly.With the gradual excavation of the foundation excavation in the subsequent working conditions in each area,the deformation of the station gradually increases,but the deformation is small and the deformation in the interval has not changed greatly.