Study On The Influence Of Ground Settlement Of Shield Tunnel In Sand Stratum

In accordance with the monitoring data obtained during the excavation of Shenyang Metro Line1, this paper studies the influence of ground settlement of shield tunnel in sand stratum. The 3D model is established for the analysis of fluid-structure interaction during construction, in order to analyze the ground longitudinal settlement, the ground lateral settlement and porewater pressure. The single tunnel and the double tunnel are each calculated, considering the influence of groundwater seepage on land subsidence. An adaptive Kalman filter estimating equations are summarized and deduced on the basis of analyzing Kalman filtering principle, and the adaptive Kalman filter is presented step by step. The program of Data Processing is established for the adaptive Kalman filter by software Matlab, and it can verify the result of data processing by adaptive Kalman filter. In view of characteristic of the adaptive Kalman filter, analyze the monitoring data obtained during the excavation. The feasibility of use software is analyzed to simulate excavation of shield tunnel and the influence on the ground settlement caused by shield tunnel construction. For fitting the surface deformation curves based on the Peck formulaby by single regression analysis, the paper gains the two unknown parameter' the maximum ground settlement Smax' and 'sediment tank efficient i'. Analysis results show that the Finite Element Method and the Calman Filtering Prediction Method all apply to the analysis of the vertical ground surface deformation by shield tunnel, and the changing trend are in general accord. The Calman Filtering Prediction Method can preferably be used to cope with dynamic data, and has high forecast precision.