Research on the Stress and Deformation Characteristics of Circular Foundation Pit during Excavation in Sand Soil

Abstract

The stress and deformation response characteristics of the support structure in the process of excavation and support of circular sand foundation pit are complex. The existing research results lack a general analysis method for the mutual check between the field monitoring data and the numerical simulation results. This research relies on the excavation and support project of a circular foundation pit in the sandy soil layer of the west anchorage of Humen Second Bridge. The force and deformation characteristics of foundation pit soil are monitored and structure is supported during construction. A new method for checking simulation parameters based on the excursion monitoring data of the diaphragm wall is proposed. The modeling and calculation theory of foundation pit excavation and support process is established. The superposition calculation of pore water pressure is used to realize the foundation pit seepage-stress coupling. The effects of steady-state seepage conditions on the equivalent strain of foundation pit soil, the displacement of the diaphragm wall, and the axial force of the lining are compared and analyzed. The stress and deformation mechanism of the soil layer and supporting structure during the excavation and support of a circular foundation pit in the sand layer is obtained.