Study on numerical analysis of rockburst and primary support time in Cangling Tunnel

According to the excavation style and gradually adjusting of the stress after excavation in the tunnel,some typical sections are chosen to numerically analyze and forecast the status of rockburst in the whole calculational scope.According to the calculational result,some conclusions can be drawn as follows: the larger of the stress releasing coefficient has become,the area and the grade of rockburst would increase.For effectively avoiding or reducing the occurring of rockburst,the most prime support times for the different areas are given by analyzing the measuring data in-situ in this tunnel.