摘要
针对地下水库煤柱坝体长期在水浸-周期应力作用下渐进损伤问题,以陕西某矿地下水库工程为背景,通过现场调研、理论分析、实验室实验等方法分析了工作面末采阶段煤柱坝体所受应力环境,探究了周期应力以及水浸对煤体的破坏规律。结果表明:煤柱坝体形成前受采动影响存在诸多次生裂隙,形成以后受水浸以及相邻工作面的采动影响,应力呈多次循环加、卸载特征;煤体单轴压缩时抗压强度为18.40 MPa,破断载荷为36.11 kN,循环加卸载1、2、3次的破坏载荷分别为35.27、29.15、27.45 kN,表明周期应力有加剧煤体损伤的作用;随着水浸时间及加卸载循环次数的增加,煤体强度逐渐降低,无水浸加卸载1次条件下煤块强度为17.97 MPa,水浸21 d加卸载3次时强度为10.78 MPa。
For the long-term progressive damage of the coal pillar dam body of the underground reservoir under the action of water immersion-periodic stress,taking a mine in Shaanxi Province as the engineering background of the underground reservoir project,the working face was analyzed through field investigation,theoretical analysis and laboratory experiments.The stress environment of the coal pillar dam body in the final mining stage,and the damage law of cyclic stress and water immersion to the coal body were explored.The results show that there are many secondary fissures affected by mining before the formation of the coal pillar dam,and after the formation is affected by water immersion and the mining of adjacent working faces,the stress is characterized by multiple cycles of loading and unloading;the compressive strength is 18.40 MPa,the breaking load is 36.11 kN,and the failure loads of 1,2,and 3 cycles of loading and unloading are 35.27,29.15,and 27.45 kN,respectively,indicating that the cyclic stress has the effect of aggravating the coal damage;with the increase of the number of loading and unloading cycles,the coal strength gradually decreases.The coal strength is 17.97 MPa under the condition of one loading and unloading without water immersion,and 10.78 MPa when loading and unloading three times in 21 days.
作者
刘晓飞
薛宗建
牛滕冲
LIU Xiaofei;XUE Zongjian;NIU Tengchong(Zhengzhou Coal Industry Group Co.,Ltd.,Zhengzhou 450000,China;Zhongyun International Engineering Co.,Ltd.,Zhengzhou 450000,China)
出处
《煤矿安全》
CAS
北大核心
2023年第8期179-185,共7页
Safety in Coal Mines
关键词
水浸煤体
周期应力
承载特性
煤体损伤
煤柱坝体
water immersion coal body
cyclic stress
bearing characteristic
coal damage
coal pillar dam body
