PREDICTION AND COUNTERMEASURE FOR ROCKBURST IN CANGLING MOUNTAIN HIGHWAY TUNNEL

Based on the engineering geology and the measured geostress,the initial stress field is obtained by inversion.Then the circumferential stress after excavation is calculated by FEM.According to the results and combined with laboratory rock test and different judgement criteria of rockburst,the conclusion is got that the low middle class of rockburst will occur in the survey and design plases;and some countermeasures are proposed.In the construction phasef,or prediction of rockburst with more precisiont,he general rockburst condition is predicted again combined with the real situation;and the result shows that the low-middle class of rockburst diminishes correspondingly.Meanwhile,the rockburst 300–500 m in front of the cutting face is predicted by stages according to the measured geostress;and the Lusen criterion is found to be applicable.