Study on instability mechanism of anisotropic structural planes of coal and rock under unloading
-
摘要: 目前针对岩体结构面滑移失稳方面的研究未考虑开挖过程中的卸荷效应，且对煤岩异性结构面的研究较少。为了探究触发煤岩异性结构面滑移的条件及其影响因素，通过建立异性结构面力学模型，理论推导了卸荷作用下异性结构面解锁滑移的判据，采用通用离散单元法程序（UDEC）建立平滑结构面数值模型，以验证理论分析异性结构面解锁滑移触发条件的准确性，分析异性结构面解锁滑移的影响因素。研究结果表明：煤岩异性结构面解锁滑移与结构面倾角、内摩擦角及水平应力与轴向应力的比值有关；当水平应力等于轴向应力时，异性结构面始终处于稳定闭锁状态，不会发生解锁滑移；水平应力和轴向应力增大、内摩擦角减小均会增大异性结构面解锁滑移难度；对于下行解锁滑移，当结构面倾角小于
$45^\circ + \dfrac{{{\varphi _{\rm{f}}}}}{2}$ （$\varphi _{\rm{f}} $ 为内摩擦角）时，其增大会增大解锁滑移难度，大于$45^\circ + \dfrac{{{\varphi _{\rm{f}}}}}{2}$ 时其增大会减小解锁滑移难度；对于上行解锁滑移，当结构面倾角小于$ 45^\circ - \dfrac{{{\varphi _{\rm{f}}}}}{2} $ 时，其增大会增大解锁滑移难度，大于$ 45^\circ - \dfrac{{{\varphi _{\rm{f}}}}}{2} $ 时其增大会减小解锁滑移难度；对于异性结构面稳定闭锁状态，结构面倾角不大于30°时，若轴向应力大于抗压强度，则煤岩组合体发生脆性破坏。Abstract: Currently, the research on the slip instability of rock mass structural planes has not considered the unloading effect during heading. There is relatively little research on the anisotropic structural planes of coal and rock. In order to explore the conditions and influencing factors that trigger the slip of anisotropic structural planes of coal and rock, a mechanical model of anisotropic structural planes is established. A criterion for unlocking slip of anisotropic structural planes under unloading is theoretically derived. A smooth structural plane numerical model is established using universal distinct element code (UDEC) to verify the accuracy of theoretical analysis of the triggering conditions for unlocking the slip of anisotropic structural planes. The influencing factors of unlocking slip of anisotropic structural planes are analyzed. The research results indicate that unlocking slip of anisotropic structural planes of coal and rock is related to the inclination angle of structural planes, internal friction angle, and the ratio of horizontal stress to axial stress. When the horizontal stress is equal to the axial stress, the anisotropic structural plane is always in a locked state without slipping. Increase of axial pressure and horizontal pressure and decrease of internal friction angle will increase the difficulty of unlocking slip on anisotropic structural planes. For downward unlocking slip, when the inclination angle of the structural plane is less than$45^\circ + \dfrac{{{\varphi _{\rm{f}}}}}{2}$ ($\varphi _{\rm{f}} $ is internal friction action), its increase will increase the difficulty of unlocking slip. When it is more than$45^\circ + \dfrac{{{\varphi _{\rm{f}}}}}{2}$ , its increase will reduce the difficulty of unlocking slip. For upward unlocking slip, when the inclination angle of the structural plane is less than$45^\circ - \dfrac{{{\varphi _{\rm{f}}}}}{2}$ , its increase will increase the difficulty of unlocking slip. When it is more than$45^\circ - \dfrac{{{\varphi _{\rm{f}}}}}{2}$ , its increase will reduce the difficulty of unlocking slip. For the locked state of structural plane, when the inclination angle of the structural plane is no more than 30°, if the axial stress is greater than the compressive strength, the brittle failure will occur in coal rock combination. -
图 3 异性结构面微小单元体结构力学模型
Figure 3. Structural mechanical model of tiny unit body of structural plane
图 4 结构面解锁与闭锁数值化结果
Figure 4. Numerical results of structural plane unlocking and locking
图 6 异性结构面下行解锁滑移位移云图
Figure 6. Displacement nephogram of downward unlocking slip of structural plane
图 7 不同因素对结构面下行解锁滑移的影响
Figure 7. Influences of different factors on downward unlocking slip of structural plane
图 8 异性结构面上行解锁滑移位移云图
Figure 8. Slip displacement nephogram of upward unlocking of structural plane
图 9 不同影响因素对结构面上行解锁滑移的影响
Figure 9. Influences of different factors on upward unlocking slip of structural plane
图 10 结构面倾角为25°时煤岩组合体应力−时间曲线
Figure 10. Stress-time curves of coal-rock combination at 25° of structural plane angle
图 11 结构面倾角为25°时煤岩组合体裂隙演化规律
Figure 11. Fracture evolution pattern of coal-rock combination at 25° of structural plane angle
表 1 模型块体参数
Table 1. Block parameters of the model
岩性 密度/（kg·m−3） 体积模量/GPa 剪切模量/GPa 岩 2 850 50 30 煤 1 600 30 20 
下载: 导出CSV
表 2 模型结构面参数
Table 2. Structural plane parameters of the model
接触面 法向刚度/
（GPa·m−1）切向刚度/
（GPa·m−1）黏聚力/MPa 内摩擦角/（°） 非滑移区域 2 000 2 000 1.0 45 滑移区域 2 000 2 000 0 16
下载: 导出CSV
-
[1] 谢和平,周宏伟,薛东杰,等. 煤炭深部开采与极限开采深度的研究与思考[J]. 煤炭学报,2012,37(4):535-542.XIE Heping,ZHOU Hongwei,XUE Dongjie,et al. Research and consideration on deep coal mining and critical mining depth[J]. Journal of China Coal Society,2012,37(4):535-542. [2] 袁亮,姜耀东,何学秋,等. 煤矿典型动力灾害风险精准判识及监控预警关键技术研究进展[J]. 煤炭学报,2018,43(2):306-318.YUAN Liang,JIANG Yaodong,HE Xueqiu,et al. Research progress of precise risk accurate identification and monitoring early warning on typical dynamic disasters in coal mine[J]. Journal of China Coal Society,2018,43(2):306-318. [3] 袁亮. 煤及共伴生资源精准开采科学问题与对策[J]. 煤炭学报,2019,44(1):1-9. doi: 10.13225/j.cnki.jccs.2018.5048YUAN Liang. Scientific problem and countermeasure for precision mining of coal and associated resources[J]. Journal of China Coal Society,2019,44(1):1-9. doi: 10.13225/j.cnki.jccs.2018.5048 [4] 齐庆新,潘一山,李海涛,等. 煤矿深部开采煤岩动力灾害防控理论基础与关键技术[J]. 煤炭学报,2020,45(5):1567-1584.QI Qingxin,PAN Yishan,LI Haitao,et al. Theoretical basis and key technology of prevention and control of coal-rock dynamic disasters in deep coal mining[J]. Journal of China Coal Society,2020,45(5):1567-1584. [5] 窦林名, 赵从国, 杨思光, 等. 煤矿开采冲击矿压灾害防治[M]. 徐州: 中国矿业大学出版社, 2006.DOU Linming, ZHAO Congguo, YANG Siguang, et al. Prevention and control of rock burst in coalmine[M]. Xuzhou: China University of Mining and Technology Press, 2006. [6] CAI Wu,DOU Linming,CAO Anye,et al. Application of seismic velocity tomography in underground coal mines:a case study of Yima Mining Area,Henan,China[J]. Journal of Applied Geophysics,2014,109:140-149. doi: 10.1016/j.jappgeo.2014.07.021 [7] 窦林名,何江,曹安业,等. 煤矿冲击矿压动静载叠加原理及其防治[J]. 煤炭学报,2015,40(7):1469-1476. doi: 10.13225/j.cnki.jccs.2014.1815DOU Linming,HE Jiang,CAO Anye,et al. Rock burst prevention methods based on theory of dynamic and static combined load induced in coal mine[J]. Journal of China Coal Society,2015,40(7):1469-1476. doi: 10.13225/j.cnki.jccs.2014.1815 [8] 窦林名,周坤友,宋士康,等. 煤矿冲击矿压机理、监测预警及防控技术研究[J]. 工程地质学报,2021,29(4):917-932.DOU Linming,ZHOU Kunyou,SONG Shikang,et al. Occurrence mechanisim,monigoring and prevention technology of rockburst in coal mines[J]. Journal of Engineering Geology,2021,29(4):917-932. [9] 李志华,窦林名,曹安业,等. 采动影响下断层滑移诱发煤岩冲击机理[J]. 煤炭学报,2011,36(增刊1):68-73. doi: 10.13225/j.cnki.jccs.2011.s1.024LI Zhihua,DOU Linming,CAO Anye,et al. Mechanism of fault slip induced rockburst during mining[J]. Journal of China Coal Society,2011,36(S1):68-73. doi: 10.13225/j.cnki.jccs.2011.s1.024 [10] 姜耀东,王涛,赵毅鑫,等. 采动影响下断层活化规律的数值模拟研究[J]. 中国矿业大学学报,2013,42(1):1-5.JIANG Yaodong,WANG Tao,ZHAO Yixin,et al. Numerical simulation of fault activation pattern induced by coal extraction[J]. Journal of China University of Mining & Technology,2013,42(1):1-5. [11] SAINOKI A,MITRI H S. Dynamic behaviour of mining induced fault slip[J]. International Journal of Rock Mechanics and Mining Sciences,2014,66:19-29. doi: 10.1016/j.ijrmms.2013.12.003 [12] 宋义敏,马少鹏,杨小彬,等. 断层冲击地压失稳瞬态过程的试验研究[J]. 岩石力学与工程学报,2011,30(4):812-817.SONG Yimin,MA Shaopeng,YANG Xiaobin,et al. Experimental investigation on in investigation on instability transient process of fault rockburst[J]. Chinese Journal of Rock Mechanics and Engineering,2011,30(4):812-817. [13] 李振雷,窦林名,蔡武,等. 深部厚煤层断层煤柱型冲击矿压机制研究[J]. 岩石力学与工程学报,2013,32(2):333-342.LI Zhenlei,DOU Linming,CAI Wu,et al. Fault-pillar induced rock burst mechanisim of thick coal seam in deep mining[J]. Chinese Journal of Rock Mechanics and Engineering,2013,32(2):333-342. [14] 王同旭,曹明辉. 采动影响下断层渐进破坏过程及能量释放规律研究[J]. 采矿与安全工程学报,2022,39(5):992-1001.WANG Tongxu,CAO Minghui. Progressive failure process and energy release law of fault induced by coal exteaction[J]. Journal of Mining & Safety Engineering,2022,39(5):992-1001. [15] 张宁博,赵善坤,赵阳,等. 逆冲断层卸载失稳机理研究[J]. 煤炭学报,2020,45(5):1671-1680.ZHANG Ningbo,ZHAO Shankun,ZHAO Yang,et al. Mechanism of thrust fault rupture causing by unloading effect[J]. Journal of China Coal Society,2020,45(5):1671-1680. [16] 于秋鸽. 上下盘开采断层滑移失稳诱发地表异常沉陷机理研究[J]. 采矿与安全工程学报,2021,38(1):41-50.YU Qiuge. Mechanism of abnormal subsidence induced by fault slipping instability during mining on hanging-wall and foot-wall[J]. Journal of Mining & Safety Engineering,2021,38(1):41-50. [17] 蔡武. 断层型冲击矿压的动静载叠加诱发原理及其监测预警研究[D]. 徐州: 中国矿业大学, 2015.CAI Wu. Fault rockburst induced by static and dynamic loads superposition and its monitoring and warning[D]. Xuzhou: China University of Mining and Technology, 2015. [18] 左建平,谢和平,孟冰冰,等. 煤岩组合体分级加卸载特性的试验研究[J]. 岩土力学,2011,32(5):1287-1296.ZUO Jianping,XIE Heping,MENG Bingbing,et al. Experimental research on loading-unloading behavior of coal-rock combination bodies at different stress levels[J]. Rock and Soil Mechanics,2011,32(5):1287-1296. [19] 沈文兵,余伟健,潘豹. 不同倾角煤岩组合岩石力学试验及破坏特征[J]. 矿业工程研究,2021,36(1):1-8.SHEN Wenbing,YU Weijian,PAN Bao. Rock mechanics test and failure characteristics of coal-rock combination with different dip angles[J]. Mineral Engineering Research,2021,36(1):1-8. [20] 肖福坤,邢乐,侯志远,等. 倾角影响下煤岩组合体的力学及声发射能量特性[J]. 黑龙江科技大学学报,2021,31(4):399-404.XIAO Fukun,XING Le,HOU Zhiyuan,et al. Mechanics and acoustic emission energy characteristics of coal-rock combined body under influence of dip angle[J]. Journal of Heilongjiang University of Science and Technology,2021,31(4):399-404. [21] 杨永杰,马德鹏. 煤样三轴卸荷破坏的能量演化特征试验分析[J]. 采矿与安全工程学报,2018,35(6):1208-1216. doi: 10.13545/j.cnki.jmse.2018.06.017YANG Yongjie,MA Depeng. Experimental research on energy evolution properties of coal sample failure under triaxial unloading testing[J]. Journal of Mining & Safety Engineering,2018,35(6):1208-1216. doi: 10.13545/j.cnki.jmse.2018.06.017 -
点击查看大图
计量
- 文章访问数: 196
- HTML全文浏览量: 50
- PDF下载量: 11
- 被引次数: 0
