深部巨厚承压含水层采动疏水诱冲机理  

Rockburst mechanism caused by the mining-induced drainage of confined water in deep extra-thick aquifer

作　　者：窦林名 周坤友[1,3] 曹安业 侯涛[4] 巩思园 阚吉亮[1] 马小涛 DOU Linming;ZHOU Kunyou;CAO Anye;HOU Tao;GONG Siyuan;KAN Jiliang;MA Xiaotao(School of Mining Engineering,Anhui University of Science and Technology,Huainan 232001,China;School of Mines,China University of Mining and Technology,Xuzhou 221116,China;Engineering Laboratory for Safe and Precise Coal Mining of Anhui Province,Huainan 232001,China;Shaanxi Zhengtong Coal Industry Co.,Ltd.,Xianyang 713600,China)

机构地区：[1]安徽理工大学矿业工程学院,安徽淮南232001 [2]中国矿业大学矿业工程学院,江苏徐州221116 [3]安徽省煤炭安全精准开采工程实验室,安徽淮南232001 [4]陕西正通煤业有限责任公司,陕西咸阳713600

出　　处：《煤炭学报》2024年第1期351-366,共16页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(52304197);安徽省煤炭安全精准开采工程实验室开放基金资助项目(ESCMP202307);国家重点研发计划资助项目(2022YFC3004603)。

摘　　要：陕蒙地区覆岩普遍赋存较厚承压含水砂岩层,工作面涌水量大、承压含水层水位显著下降,巨厚覆岩承压含水层下冲击地压和高能矿震监测表明覆岩承压水的采动疏放具有一定的诱冲效应。为揭示覆岩承压含水层采动疏水诱冲机理,开展了流固耦合数值模拟,分析了不同孔隙水压岩体力学行为及巨厚覆岩承压含水层采动疏水条件下围岩应力-能量场演化特征,揭示了覆岩承压含水砂岩层采动疏水对围岩应力场作用机制;并考虑巨厚覆岩对围岩动静载应力作用效应,提出了覆岩承压含水层采动疏水诱冲机理。研究结果表明:覆岩巨厚承压含水砂岩层下动力显现均发生在覆岩承压水位快速下降期间,覆岩承压水的采动疏放对围岩产生应力扰动;采动疏水条件下覆岩承压含水岩层孔隙水压降低,岩层强度和承载能力增大,覆岩载荷向采场两侧转移,导致围岩应力升高、能量进一步积聚,其对围岩应力场-能量场作用程度与采场尺度和疏放程度正相关,与煤层-承压含水层距离、承压含水层岩层厚度及强度负相关;巨厚覆岩承压含水层下顶板大尺度悬臂-铰接结构导致采场围岩高静载及强动载,在覆岩承压含水层采动疏水对围岩应力场作用下,煤岩体中叠加应力超过其临界载荷且释放的总能量超过其破坏所消耗能量,诱发冲击地压,其中高静载是冲击地压发生的应力基础,矿震动载和覆岩承压含水层采动疏水导致的应力扰动是重要诱因。针对覆岩承压含水层采动疏水及巨厚承压含水层覆岩结构对冲击风险的影响特征,提出了巨厚承压水含水层注浆堵水和优化盘区尺寸的防冲措施,通过地面注浆和降低采场尺寸能够降低覆岩承压含水层采动疏水对围岩应力场的作用效应、避免巨厚覆岩形成大尺度悬臂-铰接结构,从而降低巨厚承压含水层下冲击地压风险。Extra-thick sandstone confined aquifer is widely spread in the overburden strata in Shaanxi and Inner Mongolia provinces.During coal mining,the water inflow in the working face is severe and the confined water level in the roof aquifer decreases significantly.The monitoring of rockbursts and high-energy seismicity shows that the mining-induced drainage of the confined water in the extra-thick sandstone confined aquifer has a certain effect on inducing rockburst.For a better understanding of rockburst mechanism as a result of the drainage of the roof confined water,the fluid-solid coupling numerical simulations were carried out.The mechanical behavior of rock mass with different pore water pressures and the evolution of stress-energy field in surrounding rock under the condition of mining-induced drainage of the confined water in the overburden aquifer were analyzed,and the effect of the mining-induced drainage of the confined water in aquifer on the stress field in surrounding rock was determined.On this basis,considering the effect of extra-thick strata on the dynamic and static stress in surrounding rock,the rockburst mechanism caused by the mining-induced drainage of the confined water in aquifer was proposed.The results show that the dynamic behaviors under extra-thick confined aquifer,including rockbursts and high energy seismicity,occur during the rapid drop of water level in overburden confined aquifer,and the mining-induced drainage of confined water causes stress disturbance to surrounding rock.Under the condition of mining-induced drainage of the confined water,the pore water pressure of the confined aquifer decreases,the strength and bearing capacity of the sandstone strata increase,and the overburden load is transferred to both sides of the goaf,which results in the increase of the stress and elastic energy in the surrounding rock.The effect of the mining-induced drainage of the confined water in aquifer on the stress-energy field is positively correlated with goaf scale and drainage degree,and negati

关 键 词：深部开采 巨厚承压含水层 采动疏水 采动应力场 诱冲机理 

分 类 号：TD324[矿业工程—矿井建设]