尾矿库下开采合理矿柱高度留设及爆破动力分析

Reasonable Pillar Height and Blasting Dynamic Analysis for Mining Under Tailings Pond

为保证尾矿库下安全回采,防止尾矿库水体通过采动裂隙进入采场对采场安全生产造成影响.本文对尾矿库下开采引起的“三带”高度进行分析计算,通过理论计算得出防水安全岩柱的厚度应大于135.28 m.利用HOEK-BROWN非线性破坏准则获得岩体力学参数,在安全岩柱厚度为135.28 m条件下,通过数值模拟研究不同开采模式下“三带”高度和裂隙发育状态,采用普通采矿方法开采,导水裂隙带已发育到尾矿库底,对开采造成极大影响;采用充填采矿法后,导水裂隙带高度未发育至库底,处于较为安全的状态.并对尾矿库底构筑物进行爆破动力学分析,爆破震动后库底测点震动速度曲线出现双峰形态,最大震动速度为1.1397E-6 cm/s,满足安全规程要求,爆破振动对尾矿库水工构筑物影响较小,不会造成破坏.

In order to guarantee the safety of the mining operation under the tailing pond and prevent the water in the tailing pond from infiltrating to make adverse influence to the mining operation in mining stopes,the height of the Three Zone(TZ)is calculated.Through theoretical calculation,the thickness of waterproof safety rock pillar should be greater than 135.28 m.Rock mass mechanics parameters are obtained through HOEK-BROWN failure criterion.Under the condition of the safety thickness of rock pillar is 135.28 m,the“three zones”height and fracture state are studied by numerical simulation under different mining mode.With common mining methods,water-conductive fissure zone has been developed to reach the bottom of the tailings,leading to a great impact on mining.Using the filling mining method,the water-conducting fracture zone has not developed to the bottom of the reservoir and is in a relatively safe state.The blasting dynamics of the bottom structure of tailings pond is analyzed.The vibration velocity curve of the measuring point at the bottom of the tailings reservoir shows a double-peak shape,and the maximum vibration velocity is 1.1397E-6 cm/s,which meets the requirements of safety regulations.The blasting vibration has a very limited influence on the hydraulic structure of the tailings reservoir and will not cause damage.