Numerical Simulation And Stability Analysis Of Deep Excavation Construction Based On The FLAC^3D

Society is still in rapid development at present,cities also require more space to meet people's basic needs such as daily travel.So people began to develop valuable underground space resource,more and more cities began to aggressively building the subway,pedestrian crossing and other underground project,what comes next is a lot of foundation pit.Foundation pit is an important part of the underground engineering,and foundation pit stability need special concern.With the development of computer,numerical simulation is applied to the foundation pit engineering.Numerical simulation has the guiding role for the excavation construction process,and it can ensure the safety of excavation construction process.This paper rely on the foundation pit of metro station of Dalian Maritime University and the underground pedestrian passageway of Guiyang,simulate excavation construction process based on FLAC^3D,and then carry out stability analysis of foundation pit based on the results of numerical simulation.The metro station of Dalian Maritime University has plentiful groundwater,it needs to consider the impact of groundwater in the numerical simulation and fluid-solid coupling numerical method also used in excavation.First,simulation calculation foundation dewatering and analysis the variation of groundwater level and pore water pressure of model.In the process of simulation excavation and support,main analysis deformation law of the soil outside and enclosure structure.Comparing the simulation results with the measured results,both can better match.And the deformation of the soil outside and enclosure structure are also in line with the general law.The numerical simulation results feedback to the construction process,which can be used to guide the field construction.For the underground pedestrian passageway of Guiyang,this paper carry out stability analysis of foundation pit based on yielding approach index?YAI?.Using fish language preparation YAI function,and then calculated the YAI of all the soild elements.Comparative analysis the plastic zone and the YAI contour,the YAI can be better reflected failure region of model.This paper simulation foundation pit under different excavation and support process,and analyzes the dangerous area of different conditions based on YAI.We can predictive the development of failure zone caused by excavation disturbance and determine dangerous area of soil based on YAI,and it can judge the stability of the excavation pit as a basis.