远爆区爆破对胶结充填体损伤特性研究

Study on the Damage Properties of Cemented Filling Body by Blasting in the Remote Blasting Area

在回采矿柱时,开采爆破可能造成充填体强度下降和失效,充填体强度对某些采矿方法能否有效应用起到决定作用。利用自制扰动流变效应实验装置对4种不同浓度的充填体试件进行多次低强度扰动实验,结合波速变化和数值模拟手段判断充填体损伤情况。研究结果表明:浓度和竖向受力大小是影响充填体抗扰动能力的重要因素;充填体在静置养护过程中,产生重力沉降,形成"梯度结构材料",在低强度动力扰动下,上部相对损伤最大,中部次之,下部最小。充填体受多次邻侧低强度动力扰动,塑性区发展主要在前期,集中部位主要为距爆源最近的暴露面上部和最远的暴露面下部区域。研究成果对降低矿柱回采贫化率和开采成本及提高采场安全稳定性具有重要的借鉴意义。

In the process of mining pillar,mining blasting would cause the decline and failure of filling body strength,but the filling body strength plays a decisive role for effective use of some mining methods.Multiple low intensity disturbance experiments of filling body specimens with four different concentrations were carried out by the self-made disturbance rheology effect experiment device.Combined with wave velocity variation and numerical simulation means,the damage of filling body was evaluated.The research results showed that the concentration and the vertical force were important factors affecting the disturbance resisting ability of filling body.In the process of placing curing,the filling body had gravity sedimentation and formed"gradient structure materials".Under the low-intensity dynamic disturbance,the upside had the maximum relative damage,followed by the middle and the bottom.The filling body was disturbed by multiple low-intensity dynamic in the adjacent side.The plastic zone was mainly developed in the early stage.And the concentrated areas were mainly in the upside of exposed surface closest to the explosion source and in the bottom of exposed surface furthest to the explosion source.This study had an important reference significance for reducing the dilution rate and mining cost of pillar recovery,as well as improving the safety and stability of stope.