Study On The Deformation Management Level And The Information Management System Of Large Deep Foundation Pit

Foundation pit stability is a classic research field in geotechnical engineering.With the development of economic and social progress,the rigid demands for energy,resources,and transportation are increasing,which makes the foundation pit engineering construction towards a more intensive,more efficient and safer trend.During the deep foundation pit construction,not only the safety of the building to be built should be considered,but also the adverse impact of the foundation pit construction on the existing buildings should be considered.Therefore,the establishment of the deformation management level and the development of the engineering information management system for deep foundation pit engineering have important scientific significance and engineering practice value to ensure the safety of buildings to be built and existing.Take a large soft soil deep foundation pit in Wuhan as an example,FLAC3 D was adopted in this study to carry out the excavation and support process simulation of the foundation pit based on the field monitoring data.The most suitable constitutive model for the numerical simulation of deep foundation pits is selected by comparison analysis.A deformation management level for deep foundation pit was established based on the numerical simulation of deep foundation pit construction and the field monitoring data.An information management system for deep foundation pit construction was developed.The main research results were as following:(1)The simulation results obtained based on the Mohr ― Coulomb model,the modified Cambridge model,and the Cysoil model were compared.By comparing the settlement around the foundation pit,the uplift at the bottom of the foundation pit,and the deformation of the foundation pit supporting structure,the modified Cambridge model was regarded as the most suitable model for the numerical simulation of deep foundation pits in soft soil.The simulation result from this model is closest to the actual situation.(2)A monitoring system layout method for large deep foundation pit was proposed based on quantitative analysis by using numerical simulation.This method can not only accurately determine the main monitoring parts and secondary monitoring parts,but also meet the requirements of monitoring the foundation pit safety,reducing themonitoring cost,and improving the monitoring efficiency.(3)A method for deformation management level of large deep foundation pit considering the deformation control of surrounding buildings and structures was proposed.This method can not only realize the risk control of deformation and failure of large deep foundation pit,but also effectively control the adverse impact of large deep foundation pit excavation on the existing buildings/structures,and has significant operability and practical value.(4)An intelligent assistant management system for the construction process of large deep foundation pit was developed.The system includes three parts: the integrated management and unified release of three-dimensional design results,the comprehensive management and analysis of field safety monitoring results,and the integrated management and visual display of geotechnical engineering numerical simulation results.It can not only improve the safety of the project construction process,but also improve the management efficiency in the construction process.