露天转地下采深影响下爆破振动速度传播规律

Propagation Law of Blasting Vibration Velocity Influenced by Mining Depth during Transition from Open-pit to Underground Mining

为研究采矿深度影响下爆破振动速度的传播规律,以大冶铁矿东露天采场狮子山北帮边坡露天转地下开采工程实际为背景,运用ANSYS/LS-DYNA建立简化模型对矿山露天开采以及不同采矿深度的地下开采爆破过程进行模拟,并用现场实测数据对模拟结果进行了验证。分别研究了不同采深影响下边坡面质点、坡体内质点、坡面同一质点以及同一采深条件下坡体内质点振动强度特征及其爆破振动速度传播规律。结果表明:(1)与露天开采爆破相比,地下开采引起的质点振动速度衰减更趋缓慢;(2)随着采矿深度的增加,坡体内径向、切向和垂直三个方向上的质点振动速度均具有放大效应,但当爆心距超过一定范围后,爆破振动速度放大效应消失,仍表现为为随爆心距增加而衰减的效应。(3)随爆心距的增加,坡面质点垂直振动速度随采矿深度增加以放大效应为主,水平方向的质点振动速度在一定的距离范围内相差不大,不具有明显的放大或衰减效应。

In order to study the impact of mining depth on propagation of blasting vibration velocity, by taking the background of Shizi Hill north wall slope from open pit to underground mining engineering in Daye Iron Ore east as example, the simplified model of mine open pit mining and underground mining exploitation in different depths was established to simulate the detonation process by ANSYS/LS-DYNA. The analysis results were proved by field blas- ting tests. Through the influence of different mining depth on the slope surface, inner the slope, the same particle on the slope surface and the influence of same mining depth in the slope of particle to analyze vibration strength charac- teristics and the propagation of blasting vibration velocity. The analysis results show that, with respect to open-pit mining, the particle velocity caused by underground mining become more slow decay. With the increase of mining depth, particle velocity in radial, tangential and vertical of three directions has amplification effect, but blasting distance exceeds a certain range, particle vibration velocity showed attenuation effect dominates with blasting distance increased and amplification effect disappeared. With increased distance of the blast center, particle vertical vibration velocity on the slope amplification of the depth of mining increased, but in the horizontal direction within a certain distance has little difference, there is not a significant amplification or attenuation effect.