摘要
豫灵镇10000m深平洞,在埋深超过800m、巷道穿越灰白色大理岩或灰岩时常发生岩爆事故。为了控制岩爆,依据巷道地压分布规律,借助爆破震动,引起巷道两帮和端面前方的应力峰值向岩体深部转移,释放部分集中应力,增强减压区的承载能力。本文通过现场最大超深比、最小超深比与最多超深孔数、最少超深孔数的正交爆破试验,得出呈三角形布置3个超深达到掘进循环进尺1.2～2倍的辅助眼可成功控制3400mm×3000mm巷道端面的岩爆。在巷道腰墙处离底面1.8～2.0m沿走向每间隔1.0、1.5、2.0m分别布置深2.0m的震动炮眼。试验表明,沿走向间隔不大于2.0m布置震动炮眼,可成功控制巷道两帮岩爆;如果震动炮眼间距偏小,可能在帮墙上产生爆破震动裂纹。
In the building of a horizontal tunnel of 10000m long in Xiaoqinling,Yuling town,with a buried depth of over 800m,when it goes through the gray marble or limestone,rock burst accidents often occur.In order to control the rock burst,based on the tunnel ground pressure distribution,the blasting vibration is used to shift the peak stress at the front end and sides to the deep rock mass,to release some concentrated stress,and,therefore to increase the carrying capacity of the decompression zone.The field burst tests are carried out with the largest number of times of crossing over the excavation depth,the minimum ratio of over cycle excavation depth,the maximum number of super-deep hole and the minimum number of ultra-deep hole in an orthogonal manner,and it is shown that the rock burst of the front end can be successfully controlled in the 3400mm×3000mm tunnel when three secondary blasting boreholes of 1.2 to 2 times of crossing over the excavation depth are triangularly distributed.In addition,the field burst tests are carried out at places of 1.8～2.0m high and 1.0,1.5 and 2.0m in distance along the strike in the tunnel waist wall.The results show that the side rock burst can also be successfully controlled when the distance of the vibration blasting borehole of 2.0m deep is not more than 2.0m.If the spacing of the vibration borehole is too small,the blasting vibration may lead to cracking of the wall.
出处
《科技导报》
CAS
CSCD
北大核心
2010年第18期57-59,共3页
Science & Technology Review
基金
国家杰出青年科学基金项目(50725931)
关键词
岩爆
冲击地压
爆破卸压
地压控制
rock burst
pressure bumps
stress relief by blasting
underground pressure control
