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

Figure 1

Coupling model of the roof of the surrounding rock and supporting body. is the sum of the uniform load and vibration of the roof plate, acting on the upper part of the bar; is the horizontal stress, acting on the horizontal direction of the bar; is the length of the bar and can be the span of U-shaped steel; is the thickness and can be set to unit length “1.”