In order to solve the rockburst problem caused by
hydraulic tunnel excavation under the condition of high insitu
stress, a deepburied hydraulic tunnel in Xinjiang is
taken as example, and the insitu stress data from the
tests are obtained combined the onsite hydraulic
fracturing method and the drilling sleeve core removal method. First，the distribution laws of the insitu stress
field in the deepburied hydraulic tunnel area are
studied, and the possibility of rockburst occurence is judged through strength
theory. Then, considering the effects of high insitu
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 insitu stress at the tunnel is basically around 23 MPa, and the
maximum horizontal principal stress is 28.6 MPa, which belongs to the high insitu stress tunnel. （2）The overall relationship among the threedimensional
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》〗HZtype initial insitu
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 MohrCoulomb 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.
ZHOU Yaping, JIANG Haibo
. Research on InSitu Stress Characteristics of
DeepBuried HighInSitu Hydraulic Tunnel and Prediction of
Rockburst Brittle Failure Depth[J]. Tunnel Construction, 2022
, 42(S1)
: 321
-330
.
DOI: 10.3973/j.issn.2096-4498.2022.S1.037
