Analysis Of Effects Of Excavation On Existing Adjacent Tunnels

With the advancement of urbanization unceasingly and rapidly, be the same with many countries in the world, the conflict of the rare of land source is standing out day by day. In order to utilize the land effectively, advancement and exploitation of underground space and the construction of high-rise in urban develop rapidly. During the construction, a large number of deep foundation excavations have appeared. Its scale and depth increase constantly. The engineering environment of urban deep foundation excavations is complex. Urban deep foundation excavations are generally close to some constructed buildings or adjacent existing tunnel. They influence each other and interact. In such environment, applying the traditional design theory and routine construction technology, there is an inevitable difficulty about protecting surrounding buildings or structures in construction. Many scholars, engineers and technicians have already worked a lot in the influence of adjacent environment caused by deep excavation recent years, however, difficulty remains to be solved in correlation among the deformation of the retaining structures, soil deformation around the excavations and the influence of adjacent existing tunnel.The main contents in this paper: Combined with a practical foundation works, the problem will be considered by the plane strain, then check the thickness of the cross-sectional units, draw the simplify conceptual model theory, refer to the theory of earth pressure of retaining walls and excavation of underground continuous wall or pile retaining structure design and calculation of theoretical, bring forward simplify theoretical method, Forecast as a result of structural deformation of foundation pit of the tunnel structure caused by the additional load and deformation, And select numerical geotechnical analysis software MIDAS / GTS, establish the plane strain model, And Simulate the excavation and retaining structure of the actual process of construction, Calculate and analysis of tunnel excavation caused by the structure of the additional load, stress and deformation, then compared two-dimensional numerical simulation results with theoretical calculations to simplify the calculation results.The main conclusions in this paper: Through theoretical analysis and numerical simulation results of the comparative analysis of calculation results, we obtained in the general trend is similar, However, due to the analysis of many theoretical calculations assumed that the ideas and ideals as well as the numerical simulation of a variety of simplified, make a little difference between the two, and verify the feasibility of a theoretical calculation method.