高应力下硬岩巷道掘进端面钻孔爆破卸压动态模拟

Dynamic simulated model for the destress blast for the hard rock roadway tunneling under the high geostress

为了深入研究深部高应力岩层巷道围岩钻孔爆破卸压技术,将ANSYS/LS-DYNA程序和FLAC^（3D）程序相结合,动态模拟了硬岩巷道端面的钻孔爆破卸压过程,分析了不同卸压方案的钻孔爆破卸压效果,得到了合理的钻孔布置方式及钻孔深度、装药长度。结果表明：钻孔爆破卸压可降低巷道端面的支承压力峰值,并使其向岩体深部转移;呈三角形布置超深钻孔的爆破卸压效果较一字型好;钻孔超深2 m时,即超深一个掘进循环进尺时钻孔爆破卸压的效果最好;超深钻孔全长装药爆破的卸压效果较超深部分仅孔底或半长孔装药好。钻孔超深长度及其装药长度模拟表明,动态模拟较静态爆破等效模拟更精确。

The paper intends to study the pressure relief technology of drilling and blasting for the surrounding rocks of the gold mine roadway in the deep-high stress rock strata. In the paper,we have been trying to combine the nonlinear hybrid dynamic explicit finite-element program（ ANSYS/LS-DYNA） with the fast Lagrangian explicit finite-difference program（ FLAC^（3D））,a novel method,to simulate the destress blasts dynamically in the hardrock roadway. And,then,we have analyzed the effect of pressure unloading in the boring-hole blast with the different pressure unloading schemes to obtain a reasonable drilling arrangement,the drilling depth and the charge length. The results we have gained from the aforementioned analyses indicate that the peak abutment pressure in the working face can be reduced by the advanced Boring Decompression Explosion Technique, which can then be transferred to the deeper part of the rock-mass. And,then,it would be possible for the layout of the drilling hole to influence directly the destress blasts. Furthermore,the destress blasts in the triangle hole mode has been found more and better effective than that of the straight-line one,when the hadal depth of the super-deep drilling is 2 m,which can just be recognized as an advance per round. Therefore,it is only the destress blast that should be the best. Furthermore,the full length charge blast in the ultra deep drilling has been proven to produce even more advantageous pressure relief effect than that of the unique hole bottom or half-hole long charge drilling manner in the ultra deep drilling part. Thus,it can be said that the effect of the dynamic simulation we have done turns out to be more accurate than those of the static simulation both in hadal depth of the super-deep drilling and the charge length of super-deep drilling. Therefore,the proposed method and research results can be expected to provide a ground-breaking progress in the economic stress-releasing mining approach in the similar mining cases.