Abstract:Based on the observed data of more than 70 shallow-depth-excavation tunnels,the formula for the maximum settlement of shallow-depth-excavation tunnel is deduced by analyzing all kinds of factors affecting stratum deformation. In addition,the law of stratum deformation is summarized. For example,the probability distributions of the maximum ground subsidence and the vault settlement appear to be approximately normal ones. With the decline of the stability of surrounding rock,the ground subsidence and the vault settlement increase gradually. When the tunnel span is between 5 and 10 m,the relationship between the maximum ground subsidence and the tunnel depth display convex shape with the surrounding rock of classes II,III,V. When the tunnel depth is less than 25 m,the maximum vault settlement increases with the rise of depth for tunnel with surrounding rock of classes II,III. The ratios of the vault settlement to the ground settlement are in the range of 0.5–1.5. When the depth of the tunnel is less than 20 m,the widths of the settlement trough are between 8R and 12R(R is equivalent radius). Finally,the collapse height,collapse amount are analyzed for more than 50 collapse tunnels. Furthermore,the main influential factors are discussed. The research results are of great importance and practical value to the design and construction of tunnel.