Study On The Stability Of Foundation Pit In Beijing Subway Station Of Laiguangying

Since the reform and opening-up, the economy has been booming in China andthere is prosperity in all wakes of life. In order to relieve the transportation pressure incities where a great number of people have been swarming in, the underground spacebegin to be used and explored and thus subway gradually becomes one of theprominent transportations. There are a lot of construction traffics caused by thesubway construction, which has a great influence on the surrounding soil andbuildings on the ground. Therefore, how to reduce this influence to the minimum inthe subway foundation pit program is illustrated in this paper.The current research and deformation theory of the foundation pit, the finiteelement method from my point of view, and the introduction of the characteristics andengineering applications of the MIDAS/GTS software are discussed in this paper.This paper is based on the foundation pit of the Laiguangying station entrance A ofthe14th Beijing Subway Line and analyzed by the MIDAS/GTS software. Theanalysis shows that for the horizontal displacement，the surrounding soil subsidence,bottom uplift and deformation of retaining structure in the various stages ofexcavation of the pit. And the factors that affect the stability of the excavation are alsoanalyzed in this paper.The results show that the excavation of soil deformation is mainly concentratedaround the middle of the pit in the long side while there is less deformation in theshort side. The Maintenance structure deformation is similar with this rule, that is，thelong side deformation is more serious than the short side and the uplift of thefoundation pit at the bottom of the surrounding soil deformation is the most serious.In the same geological conditions and other conditions, an increase in the depth ofexcavation will increase the deformation of the soil around the pit; the rate of increasethe rate of increase is less than the depth of the excavation. Reinforcement on thebottom of the excavation process can significantly reduce the deformation of soilexcavation and retaining structure around the pit and it is an effective way to increasestability. This article does not take the groundwater into consideration, and the influencing factors analysis is not comprehensive, therefore, it is hoped that thiswill be improved in the further study.