Statistical Analysis of Deformation and Disease of Shield Tunnel under Different Stratum Conditions

The long-term deformation and disease status of shield tunnel are different under different stratum conditions. According to the typical geological conditions of Hangzhou, the strata where the tunnel is located are classified into three typical strata, namely soft clay, upper layer-silty sand and lower layer-soft clay and silty soil. A large number of monitoring data and measured data of Hangzhou metro are summarized to study the long-term deformation and disease status of shield tunnel under different stratum conditions. The horizontal convergence and vertical displacement of the shield tunnel are small in the silty soil stratum, followed by upper layer-silty sand and lower layer-soft clay stratum, while the horizontal convergence and vertical displacement is relatively large in the soft clay stratum. The occurrence probability and severity of leakage, breakage, separation of track bed in shield tunnel ring and joint dislocation, joint opening between shield tunnel ring in upper layer-silty sand and lower layer-soft clay stratum is greater than in silty sand stratum, but less than in soft clay stratum. Relatively serious disease such as leakage of sediment, unfilled corner and defect, value of joint dislocation greater than 4mm, value of joint opening greater than 4mm, value of separation of track bed greater than 1mm are rare in silty sand stratum.