浸水煤样强度劣化机理与防隔水煤柱留设公式优化方法探讨  

Discussion on mechanism of strength deterioration of water immersion coal samples and optimization method of retaining formula for waterproof coal pillars

作　　者：徐祥宇 皇甫萌娜 马梦婷 李东宸 郭永强 徐智敏[1] XU Xiangyu;HUANGFU Mengna;MA Mengting;LI Dongchen;GUO Yongqiang;XU Zhimin(College of Resources and Earth Sciences,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学资源与地球科学学院,江苏徐州221116

出　　处：《煤炭科技》2024年第5期56-62,共7页Coal Science & Technology Magazine

基　　金：国家自然科学基金面上项目(42172272);中国矿业大学国家级大学生创新创业训练计划项目(202210290041Z)。

摘　　要：防隔水煤柱的留设是防治老空水害问题的有效措施之一,为考虑煤柱长期浸水失稳对防隔水煤柱安全留设尺寸的影响,进一步提高防隔水煤柱的安全性,以华北型煤田为研究背景,基于模拟浸泡试验实测数据,分析了煤柱浸水时的强度破坏规律,探究了强度破坏的内在原因及影响因素。结果表明:不同浸泡环境下的煤柱抗压强度均随浸泡时间的延长而降低,并最终趋于稳定;抗拉强度与浸泡时间的关系在不同浸泡条件下呈现不同的变化规律,去离子水溶液浸泡条件下仍呈降低且趋于稳定的变化趋势,在高矿化度矿井水环境下则存在临界值,并在突破临界值后再次呈现降低趋势;影响煤柱稳定性的因素包括煤岩体性质、浸泡时间、浸泡溶液水化学特征等,其中浸泡时间为主要影响因素之一。结合实测数据及上述分析,从更加安全的角度引入了煤柱软化系数以限制经验公式中的抗拉强度,将防隔水煤柱留设公式修正为:L=0.5KM√3P/R_(t)K_(p)。The retention of waterproof coal pillar is one of the effective measures to prevent and control the problem of coal mine goaf water damage,in order to consider the influence of long-term water immersion and instability of coal pillar on the safe retention size of waterproof coal pillar,and to further improve the safety of waterproof coal pillar.Taking the North China type coalfield as the background of the study,and based on the simulation of immersion test measured data,the strength damage law of the coal pillar was analyzed when it was immersed in water,and the intrinsic causes of the strength damage and the factors affecting the damage were investigated.The results show that the compressive strength of coal pillars under different immersion environments is reduced with the extension of immersion time,and eventually tends to be stable;the relationship between tensile strength and immersion time shows different patterns of change under different immersion conditions,the deionized water immersion conditions are still decreasing and tends to be stable trend,in the high mineralisation of the mine water environment,there is a critical value,and in the breakthrough of the critical value after the trend of decreasing again.The factors affecting the stability of coal pillars include the nature of coal rock body,soaking time,and the hydrochemical characteristics of the soaking solution,among which the soaking time is one of the main influencing factors.Combined with the measured data and the above analyses,the softening factor of coal pillar was introduced to limit the tensile strength in the empirical formula from a safer point of view,and the retaining formula of the waterproof coal pillar was amended to:L=0.5KM√3P/R_(t)K_(p).

关 键 词：防隔水煤柱 浸泡试验 强度破坏 水—岩反应 公式修正 

分 类 号：TD325[矿业工程—矿井建设]