【摘要】 分析了不同装药结构条件下的爆生气体初始压力及气体压力随堵塞物位移的变化规律,从牛顿第二定律入手推导出了堵塞物长度与堵塞物在爆生气体压力作用下运动时间的关系式,然后采用BCM模型对岩体裂纹扩展进行分析,定义裂纹从孔壁沿着最小抵抗线方向扩展到自由面所用的时间为岩体破碎时间,令堵塞物在炮孔中运动时间等于岩体破碎时间,建立了计算堵塞物最佳长度的理论模型,该模型综合考虑了爆生气体压力作用下堵塞物的运动和裂纹扩展导致岩体破碎这两方面。最后将理论计算值与经验值和试验值进行了对比分析,理论计算值与经验值和试验值吻合较好,证明了理论模型具有一定的可靠性。更多还原

【Abstract】 Blasting gas effect and rock crack growth have an important influence on rock breaking.The initial pressure of blasting gas under different dynamite installation structures and gas pressure’s variation with the displacement of stemming material are analyzed,from Newton’s second law the relationship of stemming material’s length and the time that it movements in hole under blasting gas pressure effect is derived.The rock crack growth is analyzed by using BCM model,the time that crack grows from hole wall to free surface along minimal resistance line is defined as rock breaking time,let the rock breaking time equal to movement time of stemming material in the hole,the calculation model for calculating stemming material optimal length is established.The model considers two aspects,which are the stemming material movement under blasting gas pressure effect and crack growth leading to rock breaking.The theoretical value is compared with empirical value and experimental value,and theoretical value is close to empirical value and experimental value,so the theoretical model has a definite reliability and can provide theoretical guidance for blasting engineering.更多还原