基于围岩损伤机理对地铁爆破参数的研究

为解决地铁爆破中存在的超欠挖问题,依据爆炸载荷作用下的岩石作用原理及围岩损伤机理,采用现场试验的方法,对地铁区间隧道原有爆破施工方案掏槽眼间距和周边眼光面爆破参数进行综合优化。结果表明:(1)爆破振速由0.956 cm/s减小为0.379 cm/s;(2)炸药单耗由2.10 kg/m3降低为1.21 kg/m3。通过现场实例验证,将围岩损伤机理应用于爆破参数设计中,在保证爆破断面平整光滑的同时,降低了炸药单耗,取得良好的经济效益;并通过优化掏槽眼参数降低振动速度,最大程度地减小对周边建筑物的扰动影响。

Research on Underground Blasting Parameters Based on Damage Mechanism of Surrounding Rock

To solve the problems of over break in underground blasting, field tests are conducted tooptimize comprehensively the parameters related to original cuthole spacing for subway tunnel blasting andperipheral hole for smooth blasting based on rock mechanism under explosive loading and damagemechanism of surrounding rock. The results show that:(1) the blasting vibration velocity decreases from0.956 cm/ s to 0.379 cm/ s;(2) the specific explosive consumption decreases from 1.21 kg / m3 to 2.10 kg / m3. The site practices prove that the damage mechanism of surrounding rock applied in the designof blasting parameters not only ensures smooth blasting section, but also reduces the specific explosiveconsumption with good economic benefit; and the optimization of cuthole parameters reduces the vibrationvelocity and minimizes disturbing influence on the surrounding buildings.