Analysis of Deformation Laws During the Construction Process of Deep Foundation Pits for Subway Stations in Silty Layer
Due to the characteristics of high water content,high thixotropy,and low strength,the silty layer is prone to problems such as excessive deformation and instability of the deep foundation pit during the construction of subway stations in the modified soil layer.Therefore,based on the Daxiaochang Station of Nanjing Metro that in a silty layer,obtains the vertical displacement,lateral displace-ment,and internal support axial force laws of the support pile top during the dynamic construction process of the foundation pit by mo-nitoring the surrounding area of the foundation pit.And a three-dimensional foundation pit model was established using finite element software to simulate the construction process of the foundation pit.The monitoring results were compared with numerical results to verify the correctness of the three-dimensional model.Finally,by comparing the calculation results of soil HS constitutive model and HSS constitutive model,a more suitable constitutive model for soft soil layer excavation analysis was identified.The research results indicate that during the excavation process of the foundation pit,the vertical and horizontal displacement of the pile top gradually increases with the construction process,and the cumulative displacement is within the warning value range;HSS better reflects the characteristics of muddy soil within a small strain range,and is more suitable for the deformation characteristics of excavation in muddy soil foundation pits.
silty layersubway stationson site monitoringfinite element simulationforce deformation
NETL
NSTL
万方数据
