Study On The Influence Of Deep Foundation Pit Construction On Surrounding Soil Deformation Of A Subway Station In Shaoxing

Controlling structural deformation has always been a hot topic in deep foundation pit engineering.Construction monitoring can control the deformation of foundation pit support structure and settlement of soil around the foundation pit in real time.It has become an important research direction to establish a finite element numerical model for foundation pit excavation and a prediction model for monitoring data to predict the development trend of deformation.Shaoxing area has complicated and changeable geological conditions,including deep soft soil layer and dense water area between rivers.This study Hang Shao inter-city railway station deep foundation pit engineering as the background,using numerical simulation and construction monitoring,curve fitting method,analyzed the deep soil caused by the construction of foundation pit deformation law,and studied the deformation of the foundation pit surrounding prediction,in shaoxing area to provide experience for future subway deep foundation pit construction reference.The main content is as follows:(1)Based on the deep foundation pit of a station of Hangshao intercity railway,the deep horizontal displacement of diaphragm wall,supporting axial force,settlement of soil around the foundation pit,horizontal displacement of ring beam and groundwater level are monitored.Through the analysis of the field monitoring data,the influence of foundation pit excavation on the deformation of soil around the foundation pit and the change law of internal force and deformation of foundation pit support structure are obtained.(2)Using the settlement groove eccentricity method,according to the measured data on the monitored section,the settlement of soil at different distances from the monitored section to the enclosure structure can be predicted.The gray GM(1,1)model and the gray Verhulst model were used to establish a prediction model for the monitoring data of soil settlement measuring points in 17 days,and the prediction results were compared with the measured values.The prediction results showed that compared with the gray Verhulst model,the prediction results of the gray GM(1,1)model were better and the data dispersion was smaller.(3)MIDAS GTS NX finite element software was used to establish a three-dimensional model of the actual project and analyze the calculation results,which mainly focused on the calculation results of horizontal displacement in the deep layer of the ground connecting wall,uplift at the bottom of the pit and settlement of soil around the foundation pit.The measured data under different working conditions are compared with the numerical simulation results.In this paper,the horizontal displacement of the ground connecting wall deep layer and the settlement of soil around the foundation pit are compared.The results show that the data obtained by the numerical simulation and the measured data are basically consistent.