【摘要】 煤矿坚硬岩巷掘进中,各爆破参数对掘进速度影响程度是尚待研究的问题。以四川煤炭产业集团广能公司下属矿井为研究背景,利用数值模拟与现场实验结合方法加以研究。根据凿岩台车钻速、钻臂特点设计掏槽角范围和孔长;按现场实际建立5个计算模型,在掏槽角、单孔药量、中心孔装药爆破等3种掏槽参数变化下,对爆破动态应力、破碎范围、掘进进尺进行量化分析和比较。研究结果显示:钻车条件下掏槽角度变化有限,因此正常掏槽角度对进尺影响较小。采用1.2 kg单孔药量时在掏槽关键区间内,有中心孔爆破时平均有效应力峰值较无中心孔爆破增加46.4%~76.7%,主要截面破碎面积增加24.7%~51.8%。如只增加药量对提高进尺效果则不明显:单孔药量增加50%,主要剖面破碎范围提高8.5%~13%,现场爆破进尺仅提高2%~10%。研究表明:掏槽中心孔爆破是影响硬岩掘进速度关键因素。更多还原

【Abstract】 Different blasting parameters may have different effects on driving speed in hard rock roadway development.The method of numerical simulation and field test from the coal mine of Guangneng Company was used to study the effects of different blasting parameters in this paper. The length and angle range of borehole were designed on the basis of drilling speed and boom’length for drilling jumbo. According to the data of the experiment mine,five blasting models were constructed by means of 3D numerical simulation. The transient stress,destructive range and advance per attack of cutting area were quantitatively analyzed and compared when blasting parameters( cutting angle,blasting charge,cut centre is or isn’t blasted) were changed. The results show that the cut angle changes within a narrow range under the conditions that hydraulic rock-drilling jumbo was used,so the advance per attack was rarely influenced by cutting angle’s variation. The average value of effective stress in the key cutting area increased by 46. 4%- 76. 7%when center holes were blasted than when weren’t with 1. 2 kg blasting charge,the destructive areas of chief sections improved by 24. 7%- 51. 8%. The increase of excavation speed wasn’t obvious when blasting charges were only add-ed under the condition that the center hole of cutting area was simultaneously blasted. The blasting charge increased up to 50%,the destructive areas of chief sections improved by 8. 5%- 13% accordingly,and the blasting footage enhanced by 2%- 10% only. The study indicates that it has a key influence on blasting footage that the center hole of cutting area is blasted in hard rock excavation.更多还原