摘要
针对西北地区采用冻结钻爆法进行掘进时井壁的安全性问题,按照相似比理论展开模型试验研究。试验模型采用1∶15的比例浇筑。通过同一位置处岩体爆破前后超声波波速变化来评价模型损伤大小。在模型顶部预留槽内均匀地固定3个速度传感器,记录每次爆破过程中各测点振动速度的大小,试验结果发现岩体径向振动速度最大,轴向振动速度其次,切向振动速度最小,岩体振动具有明显的方向差异性。冻结岩壁的损伤具有累积效应,临近炮孔位置处的岩体损伤因子大于其他部位,在高度方向上,模型上端损伤最大。岩体振动规律满足萨道夫斯基公式,其介质参数K=57.52,衰减系数α=1.74。发现第3段雷管起爆引起的测点振动速度最大,爆破引起的岩体振动在不同方向上有明显的差异性,径向振动速度最大,轴向振动速度其次,切向振动速度最小。
Model test studies based on the similarity theory was conducted to solve the safety problem of frozen rock wall in the mines driving with the freezing-blasting method. The model was constructed with a ratio of 1 ： 15. The degree of damage of the model was evaluated by the change of the ultrasonic velocity after blasting. Three velocity sensors were placed in the slot at the top of the model, and the sensors recorded the rock vibrating velocities of the measuring spots during each blasting process. Results show that the vibrating velocity is the largest in the radical direction, medium in the axial direction and the lowest in the tangential direction. The vibration has directional difference. The damage of frozen wall exhibits an obvious cumulative effect, and the damage factors near the blasting holes are larger than those in other places. In the vertical direction, the upper end of the model is damaged most seriously. The vibration of rock satisfies Sadovski formula with the media parameter K = 57.52 and the attenuation coefficient a = 1.74. The largest vibrating velocity is caused by the third group detonators in the differential blasting process, and the velocity of rock vibration is very different in different directions and is the largest in the radical direction, medium in the axial direction and the lowest in the tangential direction.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2014年第10期1945-1952,共8页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金委员会与神华集团有限责任公司联合资助项目(U1261126)
关键词
采矿工程
爆破
冻结岩石
振动速度
损伤
模型试验
mining engineering
blasting
frozen rock
vibration velocity
damage
model test
