露天矿爆破振动对边坡稳定性的影响

Influence of blasting vibration on slope stability in open pit mine

边坡一旦发生滑坡将严重影响工程的正常生产甚至威胁人员的生命安全,为了保证露天矿爆破施工对边坡的稳定性,采用5台爆破振动监测仪器进行3次爆破振动监测试验,根据不同的爆破网络连接形式对质点振速峰值和主振频率的变化规律进行分析;研究结果表明:露天矿爆破振动质点振速峰值随水平距离和高程的增加呈非线性衰减,主振频率也从高频向低频发展,为了保证边坡的稳定性,应该注重坡脚的振动破坏作用和坡顶的低频共振效应;当露天矿爆破单段最大药量从20 kg增加至60 kg时,边坡的质点振速峰值从5.3 cm/s增加至11.8 cm/s,已非常接近阈值12.0 cm/s,由此露天矿爆破施工时应控制单段最大药量且进行边坡加固处理;研究结果可为露天矿爆破施工对边坡的稳定性评价提供参考。

Once the slope slides,it will seriously affect the normal production of the project and even threaten the life safety of personnel.In order to ensure the stability of the slope caused by the blasting construction of the open pit mine,five blasting vibration monitoring instruments are used to conduct three blasting vibration monitoring tests,and the variation rules of the peak particle vibration velocity and the main vibration frequency are analyzed according to different blasting network connection forms;the research results show that the peak value of particle vibration velocity of blasting vibration in open pit mines decreases nonlinearly with the increase of horizontal distance and elevation,and the main vibration frequency also develops from high frequency to low frequency.In order to ensure the stability of the slope,attention should be paid to the vibration damage effect at the foot of the slope and the low-frequency resonance effect at the top of the slope;when the maximum explosive charge of a single section of the open pit blasting increases from 20 kg to 60 kg,the peak particle vibration velocity of the slope increases from 5.3 cm/s to 11.8 cm/s,which is very close to the threshold of 12.0 cm/s.Therefore,the maximum explosive charge of a single section should be controlled during the blasting construction of the open pit and the slope should be reinforced;the research results can provide reference for the evaluation of slope stability in open pit blasting construction.