ROCKBURST POSSIBILITY ANALYSIS USED IN-SITU STRESS INDEX AND NUMERICAL SIMULATION VALIDATION AT A UNDERGROUND WATER-SEALED OIL STORAGE CAVERN

The hydraulic fracturing technology is adopted to define the in-situ stress in the a region where will be build a underground water-sealed oil storage. The measurement result show that the maximum horizontal principal stress is about 10.0 MPa and the minor horizontal principal stress is about 6.0 MPa in the cavern depth. The possibility of the rockburst is analyzed by the Project Rock Mass Classification Criterion, Norway Barton criterion, Houfaliang criterion and the Hoek criterion. The result indicated after the underground cavern excavated, will not have the rock burst phenomenon as a result of the project perturbation. In view of present is unable to obtain the analytic solution of the redistributed stress surrounding the complex cavern, and to precisely judge the possibility of the rockburst in the excavation, the FLAC2D is used to simulate the process of the excavation and obtain the characteristic of the redistributed stress. The result indicated that extremely easy to produce the stress concentration region in some to have the rock burst phenomenon, even medium rock burst by the correction of the Barton rule, which indicate the typical rockburst rule is good at the rockburst possibility in the whole cavern, but not fit to the local cavern.