摘要
针对在残采区上行开采扰动影响下,下伏采空区遗留煤柱在动静载耦合下的失稳易引发遗留煤炭资源复采动力灾害的问题,开展了中等应变率扰动荷载和静态预应力耦合作用下的煤样损伤破坏实验,研究了幅值为静态单轴抗压强度S_(C)的30%、40%、50%及60%的扰动荷载叠加60%S_(C)的静态预应力作用下煤样力学响应特征。结果表明,60%S_(C)的静态预应力并未对煤样造成显著损伤,幅值小于60%S_(C)的扰动荷载并不会诱使煤样发生动态破坏;小幅扰动荷载导致煤样内部原生裂隙进一步压密夯实,宏观上表现为30%S_(C)的扰动荷载作用后煤样强度的提升;随着幅值的升高,扰动荷载诱使煤样内部微裂纹萌生和扩展,扰动损伤渐进累积,幅值大于40%S_(C)的扰动荷载作用后煤样强度劣化且扰动损伤导致的强度劣化随着幅值的升高非线性增大;当幅值突破50%S_(C)阈值后,煤样塑性变形程度显著加剧,裂纹扩展速率大幅提升,表明扰动荷载对煤样的损伤效应得到进一步强化。
Under the influence of the upward mining disturbance in the residual mining area,the instability of the remaining coal pillars in the underlying goaf under the dynamic and static load coupling is easy to cause the dynamic disaster of the remaining coal resources.Aiming at this problem,the damage and failure experiments of coal samples under the coupling of medium strain rate disturbance load and static prestress were carried out.The mechanical response characteristics of coal samples under the static prestress with the amplitude of 30%,40%,50%and 60%of the static uniaxial compressive strength(S_(C))were studied.The results show that the static prestress of 60%S_(C) does not cause significant damage to the coal sample,and the disturbance load with amplitude less than 60%S_(C) does not induce dynamic damage to the coal sample.The small disturbance load leads to the further compaction and compaction of the primary cracks in the coal sample,which is manifested as the increase of the strength of the coal sample after the disturbance load of 30%S_(C).With the increase of amplitude,the disturbance load induces the initiation and propagation of micro-cracks in coal samples,and the disturbance damage accumulates gradually.The strength of coal samples deteriorates after the disturbance load with amplitude greater than 40%S_(C),and the strength deterioration caused by disturbance damage increases nonlinearly with the increase of amplitude.When the amplitude exceeds the 50%S_(C) threshold,the plastic deformation degree of the coal sample is significantly intensified,and the crack propagation rate is greatly increased,indicating that the damage effect of the disturbance load on the coal sample is further strengthened.
作者
钱瑞鹏
郝晨良
时宝
文晓泽
付玉平
QIAN Ruipeng;HAO Chenliang;SHI Bao;WEN Xiaoze;FU Yuping(School of Engineering for Safety and Emergency Management,Taiyuan University of Science and Technology,Taiyuan,Shanxi 030024,China;School of Resources and Security Engineering,Central South University,Changsha,Hunan 410083,China;Information Institute of Ministry of Emergency Management of the PRC,Chaoyang,Beijing 100029,China;College of Mining Engineering,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China)
出处
《中国煤炭》
2025年第9期46-57,共12页
China Coal
基金
国家自然科学青年科学基金项目(52525401)
国家自然科学青年基金项目(52304094)
山西省科技成果转化引导专项(202304021301046)
山西省自然科学基金面上项目(202403021221136)。
关键词
煤柱
动静载耦合
静态单轴抗压强度
扰动荷载
损伤
声发射
coal pillars
dynamic and static load coupling
static uniaxial compressive strength
disturbance load
damage
acoustic emission
作者简介
钱瑞鹏(1989-),男,山西孝义人,博士,讲师,主要从事遗煤资源绿色低碳开发与采空区功能提升方面的研究工作。E-mail:qianruipeng1@163.com;通讯作者:时宝(1989-),男,安徽宿州人,硕士,工程师,主要从事煤矿安全技术方面的研究工作。E-mail:352923556@qq.com。
