摘要
针对分段空场嗣后充填采矿法中扇形孔爆破易引发充填体损伤及采场边界超欠挖等问题,以新桥磷矿地下采场为背景,采用有限元软件LS-DYNA构建数值模型,系统开展不同工况下的扇形中深孔爆破计算分析。将采场实测爆破轮廓与数值模拟结果进行对比,分析了不同荷载施加方式对爆破损伤预测精度的影响。数值模拟中分别引入实测孔壁压力时程加载及基于炸药材料—JWL状态方程的加载方法,实测荷载时程更能准确表征爆破效应。在此基础上,以两帮距和起爆微差时间为主要变量,对一步骤回采、二步骤回采及特殊采场条件下的扇形孔爆破过程开展系统模拟分析,并分析了围岩损伤分布规律及爆破振动特性。结果显示:一步骤回采两帮距对围岩稳定性影响较小,而起爆微差时间是控制爆破块度的主导因素。当两帮距在0.3 m时,爆破损伤主要集中于落矿区内,既能实现岩体整体破碎,又可显著降低围岩损伤风险。二步骤回采充填体稳定性对孔底距高度敏感,当孔底距大于0.6 m时可显著降低破坏风险,逐孔起爆虽能改善块度,但会加剧充填体损伤。特殊采场中,两帮参数不宜采用对称设计,应通过优化布孔降低充填体受损概率。基于研究成果,提出了适用于新桥磷矿a层矿的扇形孔爆破参数优化方案,为充填采矿法中的爆破设计提供参考。
To address the issues of backfill damage and stope boundary irregularities caused by fan-shaped borehole blasting in sublevel open stoping with subsequent backfilling,this study focuses on the underground stope of Xinqiao Phosphate Mine as a case study.Numerical models were developed using LS-DYNA finite element software to comprehensively analyze the blasting performance of fan-shaped medium-deep holes under various operational conditions.Field-measured blasting contours of the stope were compared with numerical simulation results to evaluate the influence of different loading application methods on the blasting damage prediction accuracy.The simulations employed both experimentally recorded borehole wall pressure time-histories and a constitutive explosive material model coupled with the JWL equation,revealing that the measured load time-histories yielded more precise blasting effect representations.Building upon this foundation,the study systematically simulated fan-shaped blasting under one-step mining,two-step mining,and special stope conditions by examining two key variables:inter-sidewall distance and initiation delay time.Subsequent analysis focused on surrounding rock mass damage distribution patterns and blasting-induced vibration characteristics.Results indicate that in one-step mining scenarios,inter-sidewall distance exhibits limited impact on surrounding rock mass stability,while initiation delay time emerges as the predominant factor governing blast fragmentation efficiency.At a 0.3 m inter-sidewall distance,blasting damage primarily concentrated within the ore caving zone,achieving effective bulk fragmentation while substantially mitigating surrounding rock damage risks.In two-step mining scenarios,backfill stability demonstrates high sensitivity to toe burden distance,with damage risks markedly damage decreasing when exceeding 0.6 m.While sequential hole initiation enhanced fragmentation,it exacerbated backfill damage.Special stope conditions required asymmetric sidewall parameter design and optimized borehole arrangement to minimize backfill impacts.These findings culminate in an optimized fan-shaped blasting parameter system tailored for Xinqiao Phosphate Mine′s A-orebody,delivering both theoretical frameworks and practical methodologies for backfill mining blasting operations.
作者
任少峰
吴立波
王大龙
彭世刚
刘恺
陶明
徐源泉
REN Shao-feng;WU Li-bo;WANG Da-long;PENG Shi-gang;LIU Kai;TAO Ming;XU Yuan-quan(Guizhou Fulin Mining Co.,LTD.,Fuquan 550509,China;School of Resources and Safety Engineering,Central South University,Changsha 410083,China)
出处
《爆破》
北大核心
2026年第1期74-90,共17页
Blasting
基金
国家自然科学基金面上项目(52274105)。
关键词
扇形孔爆破
数值模拟
参数优化
孔壁压力
fan-shaped hole blasting
numerical simulation
parameter optimization
borehole wall pressure
