基于环形自由面岩土高效爆破的研究与应用

Research and application on efficient rock blasting based on circular free surface

针对岩石巷道掘进循环进尺慢,炮孔利用率低的问题,采用取岩芯技术在岩土中形成环形自由面,利用少量炸药即可达到高效爆破的效果。首先对取岩芯爆破模型进行数值模拟,对爆炸效果进行预估,并得到相关爆破参数;之后根据模拟结果进行爆破实验,制作两组水泥模型,分别模拟取岩芯爆破与传统爆破,在模型外部布置测振仪,测量爆炸过后模型的相关振动数据,并对两组模型的爆破效果与振动数据作出比较,得出取岩芯模型爆破效果及爆破振动要明显优于传统爆破模型。最后将该技术应用在某岩巷掘进现场进行爆破实验,取得成功。实验结果表明,利用取岩芯技术成形环形自由面进行爆破,可以减少炮孔数,降低炸药单耗,控制住爆破振动,提高爆破效率,达到高效爆破的目的,特别是该技术可应用于城市地下工程爆破。

The present work aims to improve the speed and efficiency of rock excavation by forming a circular excavating surface with the coring technique so that the smallest possible charge of explosives would be needed.At first a numerical simulation was conducted to figure out the explosive parameters,then an experiment was carried out to verify the simulation. Two concrete models were fabricated to respectively model the coring blasting and the traditional blasting,with a vibration meter installed to measure the vibration. Comparison of the vibration data and the blasting effects between the two models show that the effect and the blasting vibration of the coring blasting are significantly superior to those of the traditional blasting. And the coring technique was successfully applied to an actual excavation project. The results show that the coring technique can be applied to blasting in circular excavating surface,thus reducing the number of shot holes,controlling the blasting vibration and improving blasting efficiency. This technique can be applied in urban engineering projects.