Study On The Settlement And Control Measures Of The Railway Subgrade Under The Shield Passing Through Lianzhen

With the continuous improvement of the urban transportation system,rail transit planning and construction has become an important part of the urban transportation system.The shield method has become one of the main methods of urban underground rail transit construction due to its unique advantages.The construction technology of shield tunneling under the existing infrastructure has also become the key control object in engineering construction.Before the shield construction,adequate theoretical analysis and technical prediction should be made:first,theoretically analyze and predict the surface settlement and deformation of the existing infrastructure that may be caused during the shield construction process;Experienced to develop multiple reinforcement and protection measures to control the surface settlement value and the existing infrastructure deformation value within the safety allowable range.Taking the Huai'an Rail Transit Project under the shield through the Lianzhen railway section as the research background,in order to ensure that the settlement value caused by the shield under the Lianzhen railway subgrade is within the safe range,the article passes the settlement value caused by the shield and the settlement control measures Theoretical calculations,model tests,software simulations and references to existing construction experience methods are used for analysis.Get the following results:?1?Using the settlement theory of the double-line shield Peck superposition method to calculate the settlement of the subgrade of the railway under the shield through the town S_21max=16.68mm,S_22max=16.68mm;the settlement formula obtained by the disturbance factor correction formula S_21max=15.58mm,S_22max=16.59mm;?2?Through sand tunnel indoor over-excavation and grouting compensation model test,the soil loss rate and ground subsidence at the depth of 1D,2D and 3D are well satisfied with the quadratic relationship of the line,and the surface subsidence curve satisfies Guass Curve;the grouting compensation rate at the buried depth of 1D,2D and 3D and the surface uplift value meet a linear relationship,and the surface uplift curve also conforms to the Guass curve;and when the grouting compensation rate and the soil loss rate are equal,note Pulp compensation does not return the maximum settlement value to its original value;?3?Use MIDAS-GTS large-scale finite element software to carry out the numerical simulation of the shield under the Lianzhen Railway,analyze the grouting pressure and the surface settlement value to meet the linear relationship,perform linear relationship fitting,and analyze the settlement trough under different grouting pressures The curve change trend law and the node hour curve law;organize the monitoring data on the spot,analyze the change trend of the shield cross-section settlement groove curve and the tunnel surface center node hour curve;and verify the correctness of the numerical simulation law with the site monitoring data;?4?Through the integration of literature,the classification of settlement control measures and the relevant content of the settlement control measures adopted in the project-"Clay Shock Method"construction method were introduced."Clay Shock Method"engineering application prospects are affirmed.Figure[29]Table[9]Reference[78]...