Causation Identification and Control Measures of Deformation by Integrated Dewatering-Excavation Process Simulation of a T-Shaped Deep Foundation Pit

Abstract

Construction of subway line intersection stations will become more and more popular in the future. Research on the deformation characteristics in the construction process is the best way to ensure the safety of the foundation pit itself, the surrounding buildings, and adjacent subway stations. In this paper, the deformation characteristics of a T-shaped subway foundation pit during construction are studied by an integrated dewatering-excavation three-dimensional numerical simulation method. The results show that the main causation of the surface settlement around the foundation pit is the stratum compression caused by dewatering, and the main causation of the deformation of the diaphragm wall and the existing subway station is the soil deformation caused by excavation unloading. It is suggested that constructing a high-quality diaphragm wall, controlling the water level within the excavation foundation pit, strengthening the monitoring, and timely cement pouring of the bottom plate are key countermeasures to reduce the deformation. The research results of this paper have reference significance for similar projects.

Risk Reduction Measures and Monitoring Analysis of Deep Foundation Pit with Water in a Metro Station in Hefei

“…Liu et al [15] used field observation combined with numerical simulation to study the stress and deformation of the support structure of the deep excavation of an underground railway, and made some proposals on the monitoring and construction of the deep excavation of the underground railway according to the analysis results. Based on 3D FEA software, Zhang et al [16] conducted a deep excavating and drainage simulation for a T-shaped metro station, and analyzed deformation characteristics during excavating. Relying on a metro station in Xiamen, Zhao et al [17] investigated the deformation response of an underground foundation pit with diaphragm wall composite internal reinforcement using the method of field observation combined with numerical simulation.…”