露天台阶爆破降低大块率及边坡稳定性研究

Study on the reduction of bulk rate and slope stability by open step blasting

为了降低露天采场大块率,采取缩小钻孔间距、更换炮孔充填材料、改用底部起爆方式、增加炮孔堵塞长度、调整炮孔装药结构、优化起爆网路的方案,为研究调整后的爆破设计方案对边坡稳定性的影响,利用ANSYS-LS/DYNA数值模拟边坡在动载条件下的爆破振动速度,最后将研究方案用于工业试验。研究发现:当采场开采至最终境界时,采用调整前的爆破设计方案时,边坡的爆破振动峰值为21.12cm/s,采用调整后的爆破设计方案,爆破振动峰值为14.82cm/s,而允许的最大爆破振动速度为15cm/s;在开采112.73万吨矿石方量的工业试验过程中,调整后的爆破设计方案将采场矿石大块率降低了23%,且减少40.95万元炸药材料费和6.87万元炮孔间隔材料费。

In order to reduce the bulk rate of open-pit stope,the schemes of reducing the spacing of boreholes,replacing the filling materials of boreholes,switching to the bottom initiation mode,increasing the plugging length of boreholes,adjusting the charging structure of boreholes and optimizing the initiation network are adopted.In order to study the influence of the adjusted blasting design scheme on the stability of slopes,The blasting vibration velocity of slope under dynamic load is simulated numerically by ANSYS-LS/DYNA.Finally,the research scheme is applied to industrial test.It is found that when the stope is mined to the final limit,the peak value of blasting vibration of the slope is 21.12cm/s when the blasting design plan before adjustment is adopted,the peak value of blasting vibration is 14.82cm/s when the blasting design plan before adjustment is adopted,and the maximum allowable blasting vibration speed is 15cm/s.In the process of the industrial test of mining 1.2773 million tons of ore square,the adjusted blasting design scheme reduced the bulk rate of ore in the stope by 23%,and reduced the explosive material cost of 409,500 yuan and the drilling and filling material cost of 68,700 yuan.