爆破振动对露天矿山永久边坡稳定性的影响分析

Influence Analysis of Blasting Vibration on Stability of Permanent Slope in Open-pit Mine

为研究爆破振动对露天矿山永久边坡稳定性的影响,以卡莫亚-卡兹比兹矿群中的3个矿坑作为研究对象,对比爆破振动对于不同岩性边坡稳定性的影响。通过选择爆破测振仪并设置测振仪参数,通过振动监测得到测点的爆破振动速度,对爆破振动速度、最大一段起爆药量以及测点到爆源中心距离等数据进行整理,并按照乘幂函数进行回归分析,得出各矿爆破振动速度v与3 Q/R的趋势线,进而得到对应矿坑的爆破振动公式,根据振动公式来预测爆破振动。为得出测点到爆源中心距离和最大一段起爆药量对边坡振动速度的影响大小,把距离与药量作为影响因子,把爆破振动速度作为因变量,并根据各矿拟合得出的爆破振动公式分别计算振动速度,制定九组实验方案;采用SPSS软件进行方差分析,得出测点到爆源中心距离这一因素对于爆破振动速度敏感性较高,对于矿坑边坡振动的影响较大;因此对于卡兹、东二软岩边坡,采取预留2~3排孔作为非爆破区域,采用机械挖掘修坡;对于南二中硬岩石边坡,采用提前进行预裂爆破来减弱爆破振动对边坡稳定性的影响。该研究成果对于刚果(金)其他相同地质条件的露天铜钴矿爆破施工有借鉴及应用的价值。

In order to study the influence of blasting vibration on the stability of permanent slopes in an open-pit mine,this paper takes three pits in the Kamoya-Kazibizi mine as the research object,and compares the effects of blasting vibrations on the stability of the slopes with different rock characteristics.By collating the measured blasting vibration data,the maximum charge per delay and the distances from the measuring points to the center of the blast source,the blast vibration attenuation law and curve are obtained by regression analysis with a power function,which can be used to predict future blasting vibrations.In order to obtain the influence of the distance from the measuring point to the center of the blast source and the maximum charge per delay on the vibration velocity,the distance and charge are taken as the influence factor,and the blasting vibration velocity is taken as the dependent variable.Based on the vibration velocity calculated according to the fitted blasting vibration formula of each pit,nine groups of experimental schemes are designed.Using SPSS software to carry out variance analysis,it is concluded that the distance between the measuring point and the center of the blast source is highly sensitive to the blasting vibration velocity,and has a greater impact on the mine slope vibration.Therefore,for the soft rock slopes of Kazibizi mine and East No.2 mine,2~3 rows of holes are reserved as a non-blasting area,and mechanical excavation is used to trim the slopes.For the medium hard rock slope of South No.2 mine,pre-split blasting is used to reduce the impact of blasting vibration on the slope stability.The research results have reference and application value for other open-pit copper-cobalt mines in Congo.