Study On Influence Of Excavation Unloading Of Soft Soil Foundation Pit On Subway Segment Structure

As the pace of urbanization accelerated.The new urban buildings will have an effect on the existing subway tunnel,which causes the structure of the subway lining and the deformation of the soil and soil inside and outside the pit.Taking the foundation pit of No.48 block as an example,the foundation pit excavation is simulated by the engineering analogy and the MIDAS/GTS finite element simulation software.Analysis of the influence of the excavation process on the tunnel structure and the surrounding strata in the surrounding subway line 1 and line 4.Guarantee the normal operation of the subway.The results show that the deformation and displacement of the tunnel lining structure is less than 10 mm during the excavation of the soft soil foundation.The software simulation analyses the horizontal displacement of the soil after the diaphragm wall and the actual monitoring situation.Through the analysis and comparison,when the thickness of the diaphragm wall is 1000 mm,the displacement of the subway tunnel is satisfied,and the displacement of the surrounding stratum is small.It is in conformity with the economy and rationality.It also summarizes the relevant suggestions for the construction safety of soft soil foundation pit excavation construction support means,monitoring methods,construction control and so on.