截齿破岩机制及截线间距优化试验研究

根据截齿侵入岩石的断裂特征和相关试验数据，分析了破岩机制及不同截线间距对破岩效果的影响。在单刀旋转截割试验平台上，以不同切削深度和截线间距进行组合试验，并结合比能耗、粗度指数及截割载荷3个评价指标，对截线间距进行优化，研究截割该类型砂岩时截线间距与切削深度的最佳比值。试验结果表明，岩石在单齿旋转截割作用下的破碎过程大致可以分为初始压碎区细粒岩屑生成、密实核形成并储能、各向裂纹的扩展与连通、断裂体崩落、二次压碎区细粒岩屑生成5个阶段，且岩屑的断裂是以拉伸为主并伴随着挤压和剪切的共同作用；在最佳截割条件下，粗度指数较高，岩屑成块率增加，且比能耗低。通过分析岩石破碎过程及对截线间距的优化，可为掘进机破岩机制研究及截齿布置提供参考。

Experimental study of breakage mechanisms of rock induced by a pick and associated cutter spacing optimization

According to fracture characteristics of rock caused a pick and its related data, breakage mechanisms and breaking effects of rocks influenced by different cutter spacing are analyzed. Cutting tests with different cutting depths and cutter spacing are performed using a rotary cutting machine with a single pick. The cutter spacing is optimized by three indicators, i.e. specific energy, coarseness index and cutting force, and the optimum ratio of cutter spacing to cutting depth for one type of sandstone is determined. Experimental results show that breaking process of the sandstone is divided into five phases, i.e. the generation of fine chips in a primary crushed zone, the formation of nucleus and its energy accumulation, the extension and connection of cracks, the falling of fracture and the regeneration of fine chips in a secondary crushed zone. The fracture is dominated by tensile failure and meanwhile accompanied by squeezing and shearing failure. Under the optimum cutting conditions, the higher coarseness index occurred when the rate of blocks is increased, and specific energy is lower. Through analyzing rock breaking process and the optimization of cutter spacing, it provides reference for breakage mechanism of rock by the roadheader and its pick arrangement.