煤矿火烧岩爆破破碎机理及爆破参数优化OA北大核心CSTPCD

In order to solve the problem of unsatisfactory bench blasting effect of burnt rock in coal mine,through the combination of theoretical analysis,numerical simulation,laboratory experiment and field test,taking Dananhu No.2 open-pit coal mine as an example,the physical and mechanical properties of burnt rock,the mechanism of blasting fragmentation and the factors affecting blasting are studied,and the blasting parameters are optimized.The research shows that the strength of rock mass becomes low and easy to break after high temperature,and the cracks in rock mass are very developed.When blasting,if the crack direction is parallel to the stress wave propagation direction,the stress concentration phenomenon will occur.If the fracture direction is not parallel to the propagation direction of stress wave,the reflection and refraction of stress wave will occur at the fracture,which will shorten the action time of stress wave and aggravate the fragmentation degree of rock mass around the borehole.The use of mud to protect the hole can improve the hole forming rate of the incendiary rock step.The blasting scheme is optimized in combination with the blasting crushing mechanism of the incendiary rock.The applicability of the blasting parameter optimization is verified by the field blasting test.