Characteristics of Ground Deformation Induced by Large-Diameter Slurry Shield Construction
(1 Tunnel and Underground Engineering Research Center of Ministry of Education, Beijing Jiaotong University, Beijing 100044; 2Beijing Urban Construction Group Co. Ltd., Beijing 100088; 3 Beijing Urban Construction Design & Development Group Co. Ltd.,Beijing 100037; 4 CCCC Highway Consultants Co. Ltd., Beijing 100088)
Abstract：
Based on the large-diameter (?14.5 m) double-tube river-passing shield tunnel at Weisalu of Nanjing
city and on-site monitoring data acquired there, the process and distribution law of surface deformation induced by the construction of a large-diameter slurry shield in sand and sandy cobble strata was studied. The results indicate that vertical surface deformation of the shield tunnel includes four stages: heaving, rapid settlement, slow settlement and stabilization. Surface deformation of single-tube tunnel construction can be described by the Peck formula, with an average Vl value of 1.856% and K value of 0.423 by fitting a unimodel shape; Surface deformation of the doubletube tunnel is of a bimodal asymmetrical shape since the later tunnel construction causes the maximum surface settlement and the trough width to increase, thus the trough shape is changed. Surface deformation of the double-line
tunnel can be described by a double Peck formula, and there is no obvious correlation between the K value and the number of tunnels and the construction history, and the Vl value is related to the construction method, quality management and construction procedure.
2017, Vol. 54 