The Research Of Numerical Modeling Of Destress Blasting In A Deep Hard Rock Tunnel Wall

The control of rock burst in deep mine is the major challenge for safety of mining. Destress blasting is one of the effective measures to control the rock burst or minimize its risk. But in this field, there are many key problems in construction technology that need to be studied. The design principles of hole depth and space and explosive charge quantity for destress blasting are studied in the paper, combined with the rock burst control engineering in Wenyu Gold Mine. The major contents and results of this study are as follows:（1） The numerical modeling of destress drilling in a hard rock tunnel wall is carried out. The change laws of reasonable drilling depth and space with buried depths are put forward on the basis of the effects of destress drilling with different drilling depths and spaces under different buried depths are modeled by FLAC^3D. Subsequently, the contrast study of the destress drilling and blasting in a deep buried depth is numerically carried out, in which the destress blasting is modeled by equivalent static method.（2） The numerical simulation of destress blasting in a deep hard rock tunnel wall is carried out. The design principles of destress blasting in a deep hard tunnel wall are put forward on the basis of effects of destress blasting with different hole depths and spaces and explosive charge quantities are simulated by using a hybrid nonlinear dynamic explicit finite-element code（ANSYS/LS-DYNA） and fast lagrangian explicit finitedifference code(FLAC^3D) scheme.（3） The field test of the destress blasting in tunnel wall and shaft lining in Wenyu Gold Mine are carried out. On the basis of the testing, the concrete construction parameters of hole depth and space and explosive charge quantities are proposed.