摘要
作为回采爆破的初始自由面和爆破补偿空间,拉槽质量直接影响落矿效果。以三山岛金矿无人采矿示范区为工程背景,采用经验类比、数值模拟和现场试验等方法,分析了不同拉槽爆破参数下的矿岩损伤演化规律,得到了超挖或欠挖面积、爆破块度、自由面质点峰值速度、监测点环向应力4个指标与爆破孔网参数间的关系。结果表明:在最小抵抗线不变的情况下,随着孔间距的增加,爆破超挖或欠挖面积先减小、后增大,最优孔间距为1.4 m;在孔间距不变的情况下,随着最小抵抗线的增加,爆破大块率逐渐增加,自由面质点峰值速度和应力测点的环向拉应力峰值逐渐减小;且最小抵抗线越小,自由面爆破能量分布越均匀,确定最优最小抵抗线为0.8 m。现场中深孔拉槽爆破试验表明:采用优化后的孔网参数爆破后,块度均匀,没有明显的超挖或欠挖现象,切割槽形成质量较好,验证了理论分析结果。
As the initial free surface and blast compensation space for mining blasting,the quality of the slot directly affects the outcomes of ore falling.Taking the unmanned mining demonstration area of Sanshandao Gold Mine as the engineering background,using methods such as empirical analogy,numerical simulation,and on-site testing,the evolution law of rock damage under different excavation blasting parameters was analyzed.The relationship between the four indicators,including over excavation or under excavation area,rock fragmentation,peak velocity of free surface particles,and circumferential stress of monitoring points,and blasting hole network parameters was obtained.The results show that,under the condition of constant minimum resistance line,with the increase of hole spacing,the area of blasting over excavation or under excavation first decreases and then increases,and the optimal hole spacing is 1.4 m.Under the condition of constant hole spacing,with the increase of the minimum resistance line,the rate of large blasting blocks gradually increases,and the peak velocity of free surface particles and the peak circumferential tensile stress of stress observation points gradually decrease.The smaller the minimum resistance line,the more uniform the distribution of free surface blasting energy,and the optimal minimum resistance line is determined to be 0.8 m.The field tests on the deep hole slotting show that the optimized medium-deep network parameters could result in uniform block size,no obvious over excavation or under excavation,and good quality of cut slot formation,which verifies the theoretical analysis results.
作者
赵兴东
宋景仪
周鑫
ZHAO Xingdong;SONG Jingyi;ZHOU Xin(Labrotary of Safe Mining in Deep Metal Mine,Northeastern University,Liaoning Shenyang,110816)
出处
《爆破器材》
CAS
CSCD
北大核心
2023年第5期50-56,64,共8页
Explosive Materials
基金
国家自然科学基金重点项目(52130403)
2023年辽宁省中央引导地方科技发展资金计划项目。
关键词
拉槽爆破
爆破参数
数值模拟
岩石块度
超挖
欠挖
slot blasting
blasting parameters
numerical simulation
rock fragmentation
over excavation
under excavation
作者简介
第一作者:赵兴东(1975-),男,博士,教授,博导,主要从事深部金属矿采动灾害防控研究。E-mail:zhaoxingdong@mail.neu.edu.cn;通信作者:宋景仪(2000-),男,博士研究生,主要从事工程爆破研究。E-mail:2637581519@qq.com。
