Passive three-dimensional microseismic imaging for mining-induced rock-mass degradation

摘要

Mine development imposes stress changes in the surrounding rock that typically induce or triggerrnseismicity with a wide range of magnitudes. Seismic monitoring can provide insight into the rock deformationrnand give critical feedback to the on-going operations. We have developed a passive seismic imaging algorithmrnbased on earthquake seismology to jointly locate induced microseismic events and update the velocity of thernrock model illuminated by the seismicity.We calculate travel-time based on the fast sweeping method to accountrnfor complex 3D distribution of velocity and use the adjoint method to transform the inverse problem to a forwardrnproblem which can also be solved by the fast sweeping method. In this paper, we demonstrate the efficiencyrnand robustness of the fast sweeping and adjoint method based travel-time tomography in monitoring fracturernevolution and dynamic velocity variations.