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

Figure 8

The overall equivalent stress. The equivalent stress is based on the stress contour line to express the stress distribution in the model. It can clearly describe the variation in a result in the whole model so that it can quickly determine the most dangerous region in the model. The equivalent stress maps with contact area ratios of (a) 1/4, (b) 1/3, (c) 1/2, (d) 2/3, (e) 3/4, and (f) 1 are shown. The maximum values were 1.6939e8 Pa, 1.7734e8 Pa, 1.7192e8 Pa, 1.8352e8 Pa, 1.8613e8 Pa, and 1.1269e8 Pa, respectively.

(a)

(b)

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(f)