Study On Deformation Laws Of A Deep Foundation Pit In Tianjin

It is an important subject in engineering construction to study the deformation law of deep foundation pit,which has important application value in guiding the safety construction of deep foundation pit engineering.Tianjin Binhai new area where belongs to the paralic sedimentary strata is typical of soft soil geology,the engineering geology is complicated and construction is difficult.Therefore,it is important to monitor the deformation of soil and retaining structure of deep foundation pit in this area.Based on the background of the deep foundation pit project of a hospital in Tianjin and the deep foundation pit of the underground garage,and according to the provisions of the foundation pit surrounding environment,supporting scheme,construction conditions and relevant regulations,formulate on-site monitoring scheme of deep foundation pit engineering and determine the monitoring method,monitoring frequency,early warning value and point layout.This paper uses FLAC ^3D to establish a three-dimensional numerical analysis model,and according to the lithological characteristics of soil determine the constitutive model,analysis boundary conditions and initial conditions.During the excavation and support of foundation pit simulation,the deformation rule of surrounding rock and surrounding soil can be explored.Through the comparison of the field monitoring data and the numerical simulation value,the deformation law of deep foundation pit under different working conditions is analyzed,which provides reference for the study of the deformation law of other deep foundation pit engineering in this area.The comparison and analysis of the field measured values and the numerical simulation results verifies the rationality and feasibility of the numerical simulation in the process of deep foundation pit excavation and support,and shows the guidance in the deformation prediction of deep foundation pit construction process.The stress changes of the soil and the envelope are numerically simulated to further study the influence of the excavation and support process on the displacement and stress of the deep foundation pit and the envelope.On this basis,the relationship between soil stress and displacement of supporting structures is explored.Through the above research,it can provide reference for the numerical simulation of deed foundation pit engineering,provide guidance for the construction and deformation prediction of deep foundation pit support structure,and prevent the deformation of deep foundation pit.At the same time,it provides a way to study the relationship between deformation and stress of deep foundation pit engineering.