深埋矿体采场爆破对矿柱的损伤特性研究  

Damage characteristics of ore pillars induced by deep buried orebodystope blasting

作　　者：张翔宇 严鹏[1,2] 卢文波[1,2] 张立新 宋亮 陈明[1,2] ZHANG Xiangyu;YAN Peng;LU Wenbo;ZHANG Lixin;SONG Liang;CHEN Ming(State Key Lab of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China;MOE Key Lab of Rock Mechanics in Hydraulic Structural Engineering,Wuhan University,Wuhan 430072,China;Minmetals Mining Holdings Co.,Ltd.,Hefei 230091,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,武汉430072 [2]武汉大学水工岩石力学教育部重点实验室,武汉430072 [3]五矿矿业控股有限责任公司,合肥230091

出　　处：《振动与冲击》2023年第1期123-131,189,共10页Journal of Vibration and Shock

基　　金：国家自然科学基金(51779192);国家自然科学基金雅砻江联合基金(U1765109);湖北省自然科学基金杰出青年基金(2019CFA060)。

摘　　要：千米级矿产资源在采用房柱法开采过程中,由于深部岩体“三高”赋存环境及爆破开采的“强扰动”性,导致深部矿体开采面临难以预测灾害事故,因此高应力岩体采场爆破对矿柱的损伤机理与效应研究对深部采场作业安全具有重要意义。以陈台沟铁矿深部采场爆破开挖为背景,建立采场扇形孔爆破的三维数值模型,研究不同地应力水平下采场爆破对矿柱的损伤特性,同时从理论角度借助数值模拟阐述并验证了地应力与爆破荷载相互作用的机理。结果表明:在炮孔近区(5倍炮孔半径内),围岩主要受压剪作用,在炮孔中远区(10倍~25倍炮孔半径),围岩受环向拉应力作用明显;炮孔近区的压剪应力峰值主要由爆炸荷载的贡献,受地应力影响较小,中远区的环向拉应力峰值受地应力的影响较大,且随地应力的增大而减小;在地应力水平较小时,矿柱不同区域的损伤深度在不同地应力水平下具有不同衰减趋势,在地应力水平较大(大于20~30 MPa)时,矿柱不同区域损伤深度的衰减趋至相同程度;地应力使矿柱损伤深度减小的原因在于地应力的存在减小了矿柱内的拉应力,同时通过对拉应力影响范围的估计,给出了不同埋深采场爆破时安全距离的建议值。In process of mining kilometer-level mineral resources with the room-pillar method,due to"threehighs"storage environment of deep rock body and the"strong disturbance"of blasting mining,it is difficult to predict disasters and accidents in deep ore body mining.Therefore,study on damage mechanism and effect of high stress rock body stope blasting on ore pillars is of great significance todeep stope operationsafety.Here,taking blasting excavation of deep stope of chentaigou iron mine as the background,a 3-D numerical model of fan-shaped hole blasting in stope was established to study damage characteristics of stope blasting to ore pillars under different in-situ stress levels.Meanwhile,the interaction mechanism between in-situ stress and blast load was expounded and verified with numerical simulation from theoretical point of view.The results showed that in blast hole near region within 5 times of blast hole radius,surrounding rock is mainly subjected to compressive shear action,and in blast hole mid-far region within 10-25 times of blast hole radius,surrounding rock is subjected to obvious circumferential tensile stress;peak values of compressive shear stress in blast hole near regionare mainly contributed by blast load,and are less affected by in-situ stress;peak values of circumferential tensile stress in blast hole mid-far regionare more largely affected by in-situ stress,and they decrease with increase in in-situ stress;when in-situ stress level is smaller,damage depth in different areas of ore pillar has different decay trends under different in-situ stress levels;when in-situ stress level is larger(more than 20-30 MPa),damage depth decay in different areas of ore pillar tends to the same degree;the reason why in-situ stress reducing damage depth of ore pillar is the existence of in-situ stress reducing tensile stress in ore pillar;meanwhile,through estimating influence range oftensile stress,recommended values of safety distances for blasting in stopes with different burial depths are given.

关 键 词：扇形孔 地应力 爆破损伤 矿柱 安全距离 

分 类 号：TD235[矿业工程—矿井建设]