Abstract: The regularities of rock burst distribution along auxiliary tunnel during excavation are presented, and the measures of controlling rock burst by technology of destressing blasting and controlled blasting are discussed. The practice of rock burst controlling during the excavation of Jinping auxiliary tunnel which crosses the Jinping mountain with an average buried depth of 1 500-2 000 m is taken as a research background. The regularities of rock burst distribution along the auxiliary tunnel indicate that the rock burst should be prevented in two ways the stress concentration in surrounding rock and also the energy storage capability of surrounding rock should be reduced. Particular attention should be paid to relieve the stress in the areas in front of and both sides of tunnel face when destressing blasting methods are adopted during excavation of tunnel sections with strong and extremely strong rock burst proneness, and the distance between blast holes should be within 1-2 m, which should not be too large, or the efficiency and effectiveness of stress relieving would be reduced. In addition, the controlled blasting measures, such as improving the shape of cavern contour, adjusting drilling procedures and controlling blasting footage below 2 m, could be used to improve the stress state and reduce blasting disturbance, and they are proved to have positive effect on reducing the frequency and grade of strong and extremely strong rock burst.

Key words: Jinping auxiliary tunnel, rock burst, active control, controlled blasting