Model Test Study On The Closed Frame Structure Of Subway Affected By Xi'an Ground Fissure

With the rapid development of Xi'an's city scale, traffic problems have become increasingly prominent, the Metro project gradually put on the agenda. However, due to natural and man-made factors, more than 10 pieces of ground fissures have appeared in the area of Xi'an since the late 1970s, and are in constantly developing. These ground fissures will seriously affect the Metro project in Xi'an. Because the Metro project is unable to avert, will pass through these ground fissures, and not to allow great damage after the Metro is completed and put into operation, so to make sure how the ground fissures affect the subway structure and solve the problem seems particularly important.By large-scale (1:5) model test about the ground fissures and the closed frame structure, this paper researches how the ground fissures affect the subway closed frame structure that is built by open cut construction method in the typical depth of the layers 20.0m scope of Xi'an, including the damage of the closed frame structure, the stress and deformation of the soil near the structure, makes sure the damage form of the closed frame structure.The author established the numerical model about the ground fissures and the subway closed frame structure by MARC finite element software. By numerical calculation, the author analyzed the stress and deformation of the structure under the influence of the ground fissures, the deformation of the soil near the structure and so on. What's more, the author compared the results of the numerical analysis and the model test, and made the model test results better in order to supply scientific basis for the structure design of the No.2 subway that is built by open cut construction method when passing through the ground fissures. At last, the author made propose for the structural measures and waterproofing measures of the open cut subway when passing through the ground fissures.