Abstract: In order to solve the rockburst problem caused by hydraulic tunnel excavation under the condition of high insitu stress, a deepburied hydraulic tunnel in Xinjiang is taken as example, and the insitu stress data from the tests are obtained combined the onsite hydraulic fracturing method and the drilling sleeve core removal method. First，the distribution laws of the insitu stress field in the deepburied hydraulic tunnel area are studied, and the possibility of rockburst occurence is judged through strength theory. Then, considering the effects of high insitu stress and the secondary stress state of surrounding rock excavation, the damage depth of the rockburst is calculated through the theoretical formula of the depth of rockburst failure zone. The results show that: （1）The average initial insitu stress at the tunnel is basically around 23 MPa, and the maximum horizontal principal stress is 28.6 MPa, which belongs to the high insitu stress tunnel. （2）The overall relationship among the threedimensional principal stresses is 〖WT５《TNR#I》〗σ〖WT５《TNR》〗H>〖WT５《TNR#I》〗σ〖WT５《TNR》〗Z>〖WT５《TNR#I》〗σ〖WT５《TNR》〗h, which belongs to the 〖WT５《TNR#I》〗σ〖WT５《TNR》〗HZtype initial insitu stress field, and the horizontal tectonic stress is dominant. (3) The differential value between the maximum and the minimum principal stresses of the tunnel is large, and according to the MohrCoulomb criterion, it shows that the tunnel excavation will have a large shear stress on the free surface and easy to cause rockburst in tunnel. (4) During tunnel excavation, medium to strong rockburst will be occccrred in the tunnel, and the maximum depth of rockburst brittle failure is 0.68 m.

Key words: deepburied hydraulic tunnel, high insitu stress, insitu stress measurement; rockburst, brittle failure depth