| Roadway is a main part in underground mining. Due to its great economic and significant strengthening benefits, rock bolt becomes the main supporting method in roadway. But in practical mining, disturbance of engineering dynamic loading always causes instability of roadway.Based on numerical code-FLAC/FLAC3D, two different artificial boundary methods are studied to simulate dynamic excavation. Then the influence of different separation width on roof stability in roadway and mechanism of pretension-bolting support were analyzed in static module. Finally, the development of roadway on the bolt supporting roadway is simulated in dynamic analysis module. Dynamic responses of stress of roadway and bolting support are obtained, and the tending failure section of bolt is judged. In order to blast to pressure relief, potential dangerous zone is forecasted and parameters of blast to pressure relief are determined using elastic strain energy density method. Then, based on the built-in dynamic module, the influence of blast on the bolting support roadway is simulated. Dynamic responses of the rock bolt and stress wave attenuation law are concluded. Also, bolt location that is easy to fail is found. By above study, it presents guidance to bolting support design under dynamic loads to maintain stability of surrounding rock mass. |
PDF Full Text Request