爆破振动对龙首矿露天转地下安全顶柱稳定性影响研究  

Study on Effect of Blasting Vibration on Stability of Safety Roof Pillar for Open-pit to Underground Transition in Longshou Mine

作　　者：赵尔丞 魏昭君 沈彦丞 刘吉祥 李菊红 张春阳[4] 田小龙 ZHAO Er-cheng;WEI Zhao-jun;SHEN Yan-cheng;LIU Ji-xiang;LI Ju-hong;ZHANG Chun-yang;TIAN Xiao-long(Lanzhou Engineering&Research Institute of Nonferrous Metallurgy Co.,Ltd.,Lanzhou 730000,China;The Party School of the Communist Party of China in Baiyin City,Baiyin 730900,China;Cscec Aecom Consultants Co.,Ltd.,Lanzhou 730000,China;School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]兰州有色冶金设计研究院有限公司,兰州730000 [2]中共甘肃省白银市委党校,白银730900 [3]中国市政工程西北设计研究院有限公司,兰州730000 [4]武汉理工大学资源与环境工程学院,武汉430070

出　　处：《爆破》2024年第2期75-85,126,共12页Blasting

基　　金：国家自然科学基金(52174088)冻融裂隙岩体冲击疲劳损伤致裂定量表征及成灾机理研究。

摘　　要：为了探索爆破振动影响下龙首矿露天转地下开采安全顶柱的稳定性演化规律,结合矿区现状建立了对应的三维数值模型,通过计算获取了安全顶柱最危险截面位置,随后以最上部中段开采为例构建了最危险截面位置的二维数值计算模型。根据爆破参数和等效弹性边界的计算,得到掏槽眼、辅助眼和周边眼传递到开挖轮廓面上的爆破荷载峰值。将爆破荷载等效到开挖面后,开展了针对安全顶柱稳定性的数值计算。结果表明:每段延期爆破都产生了位移和振速峰值,且距离爆破位置最近的安全顶柱内监测点位移最大;以爆破作业位置为中心,振动速度向四周岩体球形扩散。根据爆破振速与岩石损伤判据,安全顶柱总体处于无损伤或轻微损伤状态。此外,最大主应力低于岩体抗拉强度,安全顶柱未形成明显地拉裂破坏塑性区。总体上来说,安全顶柱的设计厚度能够满足露天转地下开采需要。然而与数值模型相比,实际地质条件更为复杂,随着开采继续,仍需观察和监测安全顶柱的变化,从而确保其稳定性。This study aims to investigate the stability evolution of the safety roof pillar during the transition from open-pit to underground mining in Longshou mine under the influence of blasting vibration.A numerical calculation model was established based on the current mining area conditions.The most critical position of the safety roof pillar was determined through calculations,and a two-dimensional numerical model for this position was developed using top-level mining as an example.By calculating blasting parameters and equivalent elastic boundaries,we obtained the peak blasting load transmitted from cutting holes,auxiliary holes,and peripheral holes to the excavation surface.Subsequently,numerical calculations were conducted to assess the stability of the safety roof pillar after applying an equivalent blasting load to the excavation face.The results indicate that each delayed blast caused displacement and vibration velocity peaks,with maximum displacement observed at monitoring points inside the safety roof pillar closest to the blast site.Vibration velocity spreads spherically around the blasting operation position into surrounding rock mass.Based on criteria related to blasting vibration velocity and rock damage assessment,it can be concluded that overall there is no or only slight damage present in the safety roof pillar.Additionally,analysis reveals that maximum principal stress remains lower than tensile strength of rock mass without any significant formation of a tensile fracture plastic zone on the safety roof pillar.In general,the designed thickness of the safety roof pillar meets requirements for open-pit to underground mining.However,due to actual geological complexities beyond what is captured by the numerical model,it is essential to continuously observe and monitor changes in the safety roof pillar to ensure its stability during ongoing mining operations.

关 键 词：露天转地下开采 安全顶柱 爆破振动 数值模拟 稳定性演化规律 

分 类 号：TD235.3[矿业工程—矿井建设]