Analysis of the zoning excavation monitoring data of a narrow and deep foundation pit in a soft soil area

Abstract

In order to study the influence of the subarea excavation on the deformation and the stress behavior of the subway foundation pit, the deep horizontal displacement of the wall, the supporting axial force and the surface deformation were measured and compared with other similar pit cases according to the example of the deep foundation pit of a soft metro station in Hangzhou. The results of theoretical and experimental studies show that the excavation can reduce the aspect ratio of single foundation pit and play the spatial effect of small foundation pit, which can effectively control the lateral wall deformation and wall deformation. Higher stiffness can strengthen the integrity of the foundation pit and provide more lateral force path to prevent the excessive axial force fluctuation in the deep foundation pit, and its restrain effect is greater than the first excavation foundation pit; The difference in the distribution of buildings on both sides of the long and narrow pit will lead to different deformation of the walls on both sides, which should be paid attention to in the design and construction.