峨眉黄山石灰石矿台阶边坡爆破振速安全阀值研究

Safety threshold of blasting vibration velocity on the slope of Ermei mount Huangshan limestone stairs

爆破振速幅值的控制对边坡的稳定性起着重要的作用,以峨眉黄山石灰石矿山台阶边坡为例,采用拟静力法研究含软弱层边坡,倾角θ=15°~34°,临界高度H=5~14 m在安全系数为1.1情况下的安全阀值;采用应力判别法得出灰岩的安全阀值;采用FLAC3D有限差分法对边坡进行动力响应分析,对边坡关键监测点的位移,塑性区云图、剪应变增量云图、关键点的主振速度进行综合分析,得出边坡在临界状态下的安全阀值;通过对算例的研究分析得出,拟静力法得出的安全阀值和数值模拟动力分析的计算结果接近,互相印证了对安全阀值的取值比较合理。最后综合以上三种方法对爆破振速安全阀值进行合理取值。

For the slope stability,the amplitude of blasting vibration velocity plays an important role. A case study on the safety threshold of Ermei mount Huangshan limestone bench slope was carried out,which uses the pseudo-static method in the analysis of the slope with weak layer under the condition of dip θ = 15°~ 34°,critical height H = 5 ~ 14 m and safety factor = 1. 1. In addition,the safety thershold of limestone was also determined according to the stress criterion.Then,the FLAC3 Dfinite difference method was adopted to analyse the dynamic response of the slope,displacement of the slope at key monitoring points,plastic area cloud,shear strain increment cloud and main vibration velocities at key points,and the slope safety threshold in the critical state was achieved. Based on the results of the case study,the safety thresholds,calculated respectively by the pseudo-static method and the dynamic numerical simulation are in good agreement,and the values of the safety threshold are mutually verified to be reasonable. Finally,the above three methods were summarized to get a reasonable value of the safety threshold of blasting vibration velocity.