Unconventional methods for failures and instabilities of roadways based on StrataKing

Various long and narrow passages are inevitably formed for transportation and ventilation in undergroudn resources and energy exploitation. At depth, failures and instabilities of passages have attracted more and more attention. Using numerical simulation of surrounding rock models containing holes can save time and effort, costing relatively little but obtaining more information. However, reliable results depend on whether advanced numerical methods are used. Recently, a parallel computing system for strata movement (StrataKing) has been developed with a large calculation scale (up to 5 million elements), high calculation efficiency and obvious mining characteristics. After researches on the surrounding rock model containing holes with conventional loading (applying constant stress and velocity on the model boundary), further research, including static and dynamic combined loading, static and dynamic mode transformation and critical stress calculations was conducted. The results show that when the static load exists, the higher the amplitude of periodic impact, the greater the degree of fracture and movement of the surrounding rock of the roadway. This leads to difficulty in balance of surrounding rock of the roadway. As a result, the first impact can cause more fractures, which should be related to the fact that fractures caused by the first impact has a certain energy absorption effect. When the quasi-static calculation model is changed toward the dynamic calculation model progressively, which is more consistent with the disaster gestation and occurrence process, the cracking and movement of the surrounding rock of the roadway are more serious, showing the limitation of traditional quasi-static calculation mode. When the impact energy index is in the actual range, the critical stress of the surrounding rock of the square-profiled roadway is larger than the theoretical result (strictly applicable to circular roadways). By comparison, any shape of the roadway can be considered in StrataKing with large-scale computing capabilities, rich features and mining characteristics.