The Foundation Of Ningbo Subway Station In Cuibaili Numerical Simulation And Deformation Analysis

With the accelerating of urbanization and usage of the underground space in the city are becoming a hot spot,when we talk about the city construction.Because of bad geological conditions,large areas of foundation,deep problems the safety accidents always happen.This makes the importance of evaluation the stability of the excavation.Modeling analysis on the excavation process of metro foundation pit is carried out through Plaxis rock engineering finite element software before excavation of foundation pit by taking the foundation pit engineering of Ningbo metro line 4 Cuibaili station for example in this paper.Besides,the stress-state and strain-state of the foundation pit is evaluated.The foundation pit is deep in 16.2m and long in about 200m.As it is along the coastal sludge belt,there is huge difficulty in engineering.Through discussions into characteristics of multiple soil constitutive models,HSS(hardening soil model with small strain stiffness)adapted to multiple geological conditions is eventually selected in this paper.Besides,through analysis on empirical methods for parameters value of the structure model,the excavation process of the foundation pit is simulated by choosing proper model parameters.In the meantime,the deformation characters of the foundation pit under various support schemes are analyzed.Lastly,the analysis based on elastic foundation beam method is carried out with GEO5 rock engineering design software and it is compared with the calculation result of finite element.Meanwhile,the monitoring data is compared to the finite modeling.The reasons for error in numerical simulation are also analyzed and related experience is summarized,which thus provides valuable experience in modeling analysis in the follow-up research and foundation pit design of similar engineering.