The Soil Stability Analysis Of The Shallow Depth Excavation Of Subway Interval

In recent years, with the rapid growth of economy in our country and the accelerating pace of urbanization, more and more people flooding into the city, the city’s load increasing, affected the normal production and life of the people. In order to alleviate this problem, people began to pay attention to the development and utilization of underground space. This paper is based on the project of Beijing Metro Line seven JiuLongShan Railway Station ~ Dajiaoting station interval line segment, By using finite element software MIDAS / GTS to simulate the actual engineering, the reference value of the numerical simulation is verified. Through the simulation of different engineering conditions, the critical distance of different deformation forms of the section is determined, the longitudinal deformation law of tunnel vault and the influence of tunnel spacing on the longitudinal deformation of double line tunnel construction are discussed, the surface deformation caused by different excavation methods are analyzed, provide some reference for the follow-up project. The contents of this paper are as follows:(1)This paper is based on the Beijing metro line seven JiuLongShan Railway Station ~ Dajiaoting station interval for example, Collect the measured data, Using the finite element software MIDAS / GTS three-dimensional simulation analysis, verify the simulation analysis of the reference value, through the contrast analysis of measured data and the simulation data and analysis of the reasons for the emergence of settlement difference.(2)Discussion on the reasons of the lateral deformation of the section as a single peak curve, rather than the double peak curve, the peak point position of the single peak settlement curve is not corresponding to the ground surface in the middle position of the double line tunnel, through the measured data and the simulation results, the peak position of the single peak curve was determined, and the factors affecting the position of the peak points are analyzed.(3)Tunnel spacing is the main factor that influences the type of surface subsidence curve, and the characteristics of surface settlement curve are discussed by the simulation of 3D finite element software, The critical distance of transitions between the single peak shape curve and the double peak shape curve is discussed, through the comparative analysis of the ground settlement curve corresponding to the distance between different tunnels, the most suitable spacing in the process of the double line tunnel excavation is determined.(4)Through the discussion of tunnel vault settlement in the process of excavation, the three stages of vault deformation and the scope of each stage are analyzed, analysis of the influence of different tunnel spacing on the vertical deformation of tunnel vault, by comparing the deformation of tunnel vault and ground surface settlement, the reasons for the deviation of settlement are analyzed.(5)There are many factors that affect the settlement deformation during the excavation process, through numerical simulation analysis and comparison of settlement data of different excavation methods, the most suitable excavation method in construction is determined, and the engineering construction is optimized.