Optimization for U-Shaped Steel Support in Deep Tunnels under Coupled Static-Dynamic Loading

Figure 23

Vertical stress changes with different stress concentration factors. The black curve represents the equivalent stress of U-shaped steel with 0.8 side stress coefficient, the red curve represents the case of side stress coefficient 1.0, the blue curve represents the case where the side stress coefficient is 1.2, the pink curve represents the lateral stress coefficient of 1.5, the green curve represents the lateral stress coefficient of 2.0, and the brown represents the yield stress of U-shaped steel.