Basic Research Of Break Angle In Shallow-buried Tunnel

In design and construction of shallow-buried tunnel, we must consider many factors, of which, prevention and treatment of tunnel collapse is most important, it directly affects not only the safety of tunnel in construction but also the subsequent use in the future, while tunnel’s break angle is one of the important factors in analyzing tunnel collapse. To calculate the break angle and analysis the trend of development, we can optimize our design and construction according to the new theory, which plays a decisive role and provide convenience in routine maintenance. By in-situ monitoring in a large number of shallow-buried tunnels, it’s found that there are big differences between urban shallow-buried tunnel and mountain one both in stratum deformation and rock wall pressure. Break angle’s standard solution and the traditional way cannot well explain the nonlinear relationship between surrounding rock properties and geometric characteristics. Through the analysis of tunnel in different mode of destruction、 influence and evolution process, we can get the theoretical basis of break angle. Through the numerical way, we can get the angle in different conditions of surrounding rock properties and geometry conditions, thus more reasonably infer the collapse range of shallow-buried tunnel and determining tunnel upper load appropriately. Through the above research, we can provide some suggestions for design and construction in shallow-buried tunnel.