Multiparameter Inversion Early Warning System of Tunnel Stress-Seepage Coupling Based on IA-BP Algorithm

Figure 13

Plasticity strain diagram of surrounding rock. (a) Cloud image of surrounding rock plastic zone at the completion of the first excavation step. (b) Cloud map of surrounding rock plastic zone after the second excavation step. (c) Cloud map of surrounding rock plastic zone when excavation is completed. (d) Cloud map of plastic zone of surrounding rock after 90-day excavation.

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