综掘硬岩段深孔超前爆破研究与应用
Research and application of hard rock deep-hole advance blasting in comprehensive roadway excavation
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摘要: 针对硬岩巷道综掘施工难度大的问题,提出采用深孔超前爆破技术,以增大岩体内裂隙和损伤范围,降低综掘机切割难度。以淮北矿业集团桃园煤矿为例,进行了原岩应力作用下爆破裂隙和损伤范围的理论分析和数值模拟研究,据此设计了大直径深孔超前爆破参数,并进行现场试验研究,研究结果表明:炮孔直径75 mm、药柱直径63 mm的爆破炮孔周围0.424 m范围内的Von Mises应力在177 MPa以上,形成破裂区;损伤范围0.424~2.3 m;爆破后综掘机施工速度提高了40%~50%、而截齿消耗降低了52.4%;对爆破振动实测并分析得出爆破振动能量集中在50~160 Hz频带范围内,没有对巷道围岩及支护结构造成破坏。Abstract: Deep hole advance blasting technology is adopted for hard rock roadway excavated by comprehensive tunne- ling machine. It can increase the fracture and damage scope of rock mass,and make the comprehensive tunneling ma- chine cutting easier. Take Taoyuan Coal Mine of Huaibei Mining Group as an example,the theoretical analysis and nu- merical simulation on the blasting crack and damage range of original rock stress were conducted,on the basis of this, the parameters of large diameter deep hole advance blasting was designed and tested. The research results show that the range of Von Mises stress more than 177 MPa was 0. 424 m around blasting hole,the hole diameter was 75 mm,the charge diameter was 63 mm,and a fracture zone was formatted. Its damage range was from 0. 424 m to 2. 3 m. After blasting,comprehensive machine excavation speed increased by 40% to 50% and cutter consumption was reduced by 52. 4% . Blasting vibration measurement and analysis show that blasting vibration energy was focused on the frequency range from 50 Hz to 160 Hz,and there was no damage to the roadway surrounding rock and supporting structure.