摘要
为探究周边空孔与炮孔间距对爆破时围岩裂纹扩展和损伤的影响机制,在理论分析炮孔间距对斜入射应力波反射以及卸载波对围岩应力分布影响的基础上,结合数值模型,分析有、无周边空孔和不同炮孔间距爆破时围岩断裂、损伤的变化。结果表明:空孔与炮孔间距是发挥空孔效应的关键因素。间距较小,炸药能量利用率降低,无法发挥空孔对裂纹扩展的导向作用,围岩爆破损伤严重;间距较大,空孔对应力波的反射作用减弱,空孔效应不足以使两孔之间的裂纹相互贯通,无法满足开挖要求;炮孔间距为800~1000 mm时的爆破效果最佳。空孔的增设可将爆破的炮孔间距扩大30%。
In order to explore the influence mechanism of spacing between empty hole and blast hole on blasting crack propagation and surrounding rock damage in perimeter blasting,on the basis of theoretical analysis of the influence of borehole spacing on reflection of oblique incident stress waves and unloading waves on surrounding rock stress distribution,numerical models were combined to analyze the changes of fracture and damage under different blasthole spacing during perimeter blasting with or without empty hole.Results show that the spacing between empty hole and blast hole is a key factor in exerting the empty-hole effect.If the spacing is small,the energy utilization rate of explosives decreases,and the guiding effect of empty hole on crack propagation cannot be exerted,resulting in severe damage to surrounding rock.When the spacing is large,the reflection effect of empty hole on stress waves is weakened,and the empty-hole effect is not sufficient for the cracks between the two holes to penetrate each other,which cannot meet the excavation requirements.When the spacing between two blast holes is 800-1000 mm,the outcome of the empty-hole perimeter blasting is the best,and the addition of empty holes can increase the blasthole spacing by 30%.
作者
田国宾
戴俊
高萌
TIAN Guobin;DAI Jun;GAO Meng(College of Civil Engineering and Architecture,Yuncheng Vocational and Technical University,Shanxi Yuncheng,044000;College of Architecture and Civil Engineering,Xi'an University of Science and Technology,Shaanxi Xi'an,710054)
出处
《爆破器材》
CAS
CSCD
北大核心
2024年第4期58-64,共7页
Explosive Materials
基金
国家自然科学基金(51174159)。
关键词
爆破
周边空孔
炮孔间距
裂纹扩展
损伤控制
blasting
surrounding empty hole
spacing between blast holes
crack propagation
damage control
