The Complex Foundation Pit Stability Numerical Simulation And Supporting Technology Research In The Ningxia Road Subway Station Of Hefei

With the development of the construction industry and the increase of population density,the development and utilization of underground space is becoming more and more important.The underground structures of many high-rise buildings are designed different layers.These underground structures can be used as basement,commercial street,civil air defense project and soon.And with the development of subway construction,the safety of station foundation pit has to be taken seriously.The deep foundation pit engineering has the characteristics of great difficulties to implement and construction site narrow.We know that the planar size and the surrounding environment of the deep foundation pit are very different.Therefore,it is very important to optimize the foundation pit design scheme which can not only ensure the safety of excavation and support,but also obtain good economic benefits.In this paper,we take the deep foundation pit project of metro line 5 in Hefei area for example.This paper mainly studies the foundation pit supporting forms and encountered difficulties in the construction process and solution,specific as follows:1.This paper summarized several methods and applicable conditions of foun dation pit support and described the general situation.The advantages,disadvanta ges and applicable conditions are analyzed.In the meantime,we introduce the th eory of foundation pit excavation and generic form of foundation pit deformation.So,we need to consider the engineering geological conditions,hydrologic condition s and surroundings as a whole in order to choose a reasonable type of foundation p it support.2.The Midas GTS NX software was used to simulate the excavation process,analyze the force of foundation pit and enclosure structure,as well as check the enclosure structure applicability.In the end,foundation pit lectotype plan was made sure.3.Analysis is given mainly from deformation and internal force aspects in building envelope's construction.Next,the surface settlement and horizontal displacement of foundation pit are analyzed.4.The deformation and internal force change of fender post of foundation pit were studied under different pile diameters and pile-loading.It is necessary to find an optimal combination of support by comparing analysis the simulation results.We hope saving on costs was based on the premise that the support has enough carrying capacity.