Research On The Reasonable Construction Method Of The Small Clear Distance And Large Span Tunnel Under The Great Wall Of Ming

As a vast history of ancient Chinese building engineering, the Great Wall of Ming Dynasty in our country winds 6000 kilometers. Along with the highway network unceasing density and the highway construction demand, the highway line inevitably meets with the the Great Wall. Therefore, how to under the premise of protecting the great wall of the Ming meet requirement of the construction of highway has become a problem urgently to be solved in the engineering. Therefore, this paper studies the reasonable construction method of the large span tunnel under the Great Wall has important practical significance.The Shuidonggou small spacing and large span tunnel engineering as the research background, according to Ming Great Wall small spacing and large span tunnel construction technology requirements by the finite element software MIDAS/GTS, establishing three-dimensional numerical calculation model, of small clear distance tunnel in different construction processes, different excavation footage, different supporting stiffness under, the mutual influence laws of the cavern, surrounding rock stress and deformation of surrounding rock and beacon towers of the stability problem.To analyze the results of the research and draw the following conclusions.(1) The vault settlement of main road tunnel is the main factor that affects the settlement of Beacon Tower.(2) The influence of the excavation scheme of the upper surrounding rock of the small net distance from the upper part of the tunnel is more than that of the surrounding rock.(3) The effect of the tunnel before the tunnel is greater than the two disturbance effect of the tunnel after the tunnel.(4) Three intermediate rock pillars are in a state of increasing pressure, and the middle rock columns are moved to the side of the side road tunnel side by side.(5) Settlement in considering the beacon towers, deformation of surrounding rock, stability of surrounding rock, supporting structure stability, time limit for a project and project cost factors, selected in a staggered excavation process, short footage,0.75m steel arch frame spacing construction scheme as discussed within the scope of the most reasonable construction scheme.