Comparative Study of Excavation Length Effect on Stope Stability in Underground Mining

Numerical simulation is a powerful method to study excavation-induced stress redistribution in civil, mining, and underground geotechnical engineering. Also, the numerical simulation method can be time-consuming, especially for large-size three-dimensional models. In the field practice, underground tunnel excavation is proceeded meter by meter, while in the numerical simulation method analysis, it can speed up the excavation process. Furthermore, rational tunnel excavation length in the numerical simulation can provide important references for the in-situ field activities. In this paper, one hard rock underground mine is chosen for the study, and five different excavation length scenarios are proposed and performed to study the effect of excavation length on the stope stability in mining stopes in the numerical simulation method. Displacement, major principal stress, and damage initiation of the stope sidewalls are chosen as the indicators for comparison among the five different excavation scenarios. Also, the CPU time consumed for the simulation of the excavation process is taken into consideration. Compared with the other four excavation scenarios, scenario SCN#1 is more effective and efficient in numerical excavation simulation, especially for the numerical modeling simulation of a large size underground mine.