Creep instability rock burst mechanism and prevention technology of isolated coal mass in roadways of high-stress thick coal seam
-
摘要: 针对高应力大巷煤柱区孤立煤体在无明显采掘扰动情况下频繁发生冲击显现的现状，以山东赵楼煤矿七采区高应力厚煤层大巷煤柱为工程背景，采用理论分析、数值模拟和现场调研等方法，研究了不稳定蠕变作用下高应力厚煤层大巷围岩和孤立煤体的应力演化规律，揭示了高应力大巷孤立煤体蠕变失稳冲击机理：在高应力作用下煤层巷道围岩发生不稳定蠕变，不稳定蠕变弱化了巷道支护体系，增大了孤立煤体的应力集中程度，当大巷孤立煤体弹性承载区集中应力超过其极限承载能力时，高应力孤立煤体发生冲击失稳。建立了高应力厚煤层大巷孤立煤体蠕变失稳及冲击力学模型，推导出了大巷孤立煤体蠕变失稳冲击的力学判据，据此提出了高应力厚煤层大巷孤立煤体冲击地压防治对策，通过现场实践验证了理论分析的合理性。Abstract: In view of the present situation of frequent rock burst appearances of isolated coal body in coal pillar areas of high-stress roadways without obvious mining disturbance, taking the coal pillar of the high-stress thick coal seam in the seventh mining area of Zhaolou Coal Mine in Shandong Province as the engineering background, creep instability rock burst mechanism and prevention technology of isolated coal mass in roadways of high-stress thick coal seam are investigated though theoretical analysis, numerical simulation and on-site investigation. Firstly, the stress evolution laws induced by unstable creep instability of the surrounding rock and the isolated coal body in the roadways of high-stress thick coal seam are studied. Secondly, the mechanism of rock burst induced by creep instability of isolated coal in high-stress roadways is revealed. The results show that the overall instability rock burst is easily induced, when the concentrated stress in the elastic bearing zone of isolated coal body exceeds its ultimate bearing capacity. Thirdly, the creep instability and rock burst mechanical model for isolated coal body in roadways of high-stress thick coal seam is established, and the mechanical criterion of creep instability and rock burst of isolated coal body in roadways is deduced. Finally, the relevant measures are put forward to prevent and control this type of rock burst. The rationality of the theoretical analysis is verified through field practices.
-
Keywords:
- rock burst /
- coal roadway /
- isolated coal /
- stress concentration /
- creep instability
-
0. 引言
各向异性是黏土的基本性质之一,分为原生各向异性和次生各向异性。针对原生各向异性对黏土力学性状的影响,许多学者对与沉积平面呈不同夹角试样进行压缩、无侧限压缩和三轴压缩等试验,发现原生各向异性对黏土变形以及强度特性的影响不容忽视。
小应变剪切模量特性作为土的重要力学性质之一,也同样受到原生各向异性的影响。Simpson等[1]的研究表明,小应变剪切模量的原生各向异性对隧道及基坑周围土体变形的预测结果影响很大；Jovičić等[2]和吴宏伟等[3]分别针对伦敦黏土和上海软黏土进行研究,利用弯曲元测得两种土在低围压下水平和竖直方向上的最大剪切模量比值分别为1.5和1.21,说明对于不同种类黏土,原生各向异性对其小应变剪切模量的影响不尽相同。
结构性黏土在我国东南沿海地区分布广泛,许多工程建设涉及到此类黏土,迄今已对其小应变剪切模量进行了诸多研究,但以往的研究主要考虑孔隙比、应力水平和结构损伤等对小应变剪切模量的影响[4],而考虑原生各向异性对小应变剪切模量影响的研究较少,有必要进行系统探究。
本文对不同削样方向的湛江黏土原状试样开展不同围压下的共振柱试验,研究原生各向异性对最大动剪切模量的影响以及考虑原生各向异性的最大动剪切模量随围压演化规律的表征方法。
1. 试验材料与试验方案
1.1 试验材料与试样制备
土样取自湛江市某基坑内地下10～11 m,尺寸为30 cm×30 cm×30 cm原状块状样。表1为其基本物理力学指标与颗粒组成。由表1可见,湛江黏土具有较差物理性质,与软黏土相似,但力学性质较优,呈现上述特性的原因为其具有的强结构性[4]。
表 1 湛江黏土平均物理力学性质指标与颗粒组成Table 1. Physical and mechanical indexes and particle composition of Zhanjiang clay重度γ/(kN·m-3) 含水率w/% 孔隙比e 渗透系数K/(cm·s-1) 液限wL/% 塑限wP/% 塑性指数IP 结构屈服应力σk/kPa 无侧限抗压强度/kPa 灵敏度St 颗粒组成/% >0.05/mm 0.005~0.05/mm 0.002~0.005/mm <0.002/mm 17.1 52.98 1.44 2.73×10−8 59.6 28.1 31.5 400 143.5 7.2 8.2 39.5 20.7 31.6 图1（a）为不同方向圆柱试样示意图,定义试样轴线与土体沉积平面夹角为
α ,即竖直方向试样为90°,水平方向试样为0°。针对α 为0°,22.5°,45°,67.5°,90°方向原状样进行研究,试样规格尺寸为直径50 mm,高度100 mm的圆柱体。1.2 试验方法
试验所用设备为GDS共振柱仪,如图1（b）所示。试样的边界条件为一端固定,一端自由。通过电磁驱动系统对试样逐级施加扭矩,测得试样的共振频率和对应的剪应变,试样动剪切模量由下式得到：
G=ρ(2πfH/β)2, (1) 式中,G为试样动剪切模量,ρ为试样密度,f为共振频率,H为试样高度,β为扭转振动频率方程特征值。
试样在抽气饱和后安装至共振柱仪上,随后进行反压饱和,当B值达0.98后,进行固结,围压分别设定为50,100,200,300,400,500,600,700,800 kPa。试样固结完成后,进行共振柱试验。
2. 试验结果与分析
2.1 不同方向试样G-
γ 曲线规律如图2所示,不同方向试样动剪切模量G和剪应变
γ 的关系曲线形态与规律类似。剪切模量在小剪应变下衰减速度较小；随剪应变发展,衰减速度增大。低围压下G-γ 曲线随围压增大而上移,围压超过600～700 kPa,G-γ 曲线随围压增长而下移,与通常软黏土G-γ 曲线大多随围压增大而单调上移规律存在明显差异,说明结构性对湛江黏土G-γ 曲线规律影响较大。![]()
图 2 不同方向试样剪切模量G与剪应变γ 关系Figure 2. Relationship between shear modulus G and shear strainγ for specimens in different directions2.2 原生各向异性对最大动剪切模量的影响
湛江黏土动应力-应变关系可用Hardin-Drnevich双曲线模型表征,如下式：
τ=γa+bγ, (2) 式中,a,b为拟合参数。式（2）可以写为
1/G=a+bγ。 (3) 式（3）中,当
γ 趋近于0时,得到最大动剪切模量Gmax=1/a,利用式（3）求得不同方向试样在各围压下的Gmax。为了消除孔隙比对Gmax的影响,引入孔隙比函数F(e)=1/(0.3+0.7e2)将Gmax进行归一化处理,图3为经孔隙比函数归一化的Gmax/F(e)-围压σ3 曲线。随围压增大,不同方向试样Gmax/F(e)-σ3 曲线均呈现先上升后下降的规律,在围压为400～500 kPa即在σk 左右时,曲线出现转折。![]()
图 3 不同方向试样Gmax/F(e)与围压σ3的关系Figure 3. Relationship between Gmax /F(e) and confining pressure σ3 for specimens in different directions为了更好描述原生各向异性对最大动剪切模量的影响,定义Gmax/F(e)的原生各向异性系数：
Kα=Dα/D90°, (4) 式中,Dα定义为α方向试样的Gmax/F(e),D90°定义为90°（竖直）方向试样的Gmax/F(e)。
Gmax/F(e)的原生各向异性系数Kα与围压的关系如图4所示。相同围压下,Kα随方向角
α 变化,Kα整体上随α 增大而减小,即试样的方向越靠近水平其刚度越大,说明原生各向异性对湛江黏土最大动剪切模量Gmax的影响十分显著。湛江黏土基本单元为扁平状片堆、粒状碎屑矿物与单片颗粒,上述基本单元在沉积时,其长轴更倾向于水平方向,导致颗粒间水平方向的接触更紧密,结构更强[3],进而更靠近水平方向试样的刚度更大。![]()
图 4 不同方向试样Kα与围压σ3的关系Figure 4. Relationship between Kα and confining pressure σ3 for specimens in different directions当围压低于400～600 kPa时,同一方向试样Kα随围压增长基本保持恒定,K0°,K22.5°,K45°,K67.5°,K90°分别为1.314,1.279,1.148,1.045,1；当围压高于400～600 kPa时,同一方向试样Kα随围压增长呈明显减小趋势,不同方向试样的Gmax/F(e)差异减小。说明围压低于
σk 时,围压的增大几乎不影响原生各向异性对Gmax的影响,但当围压超过σk 后,围压的增大减弱了原生各向异性对Gmax的影响。文献[2]中伦敦黏土在围压超过屈服应力后,其水平与竖直方向试样的最大剪切模量的差异随围压增长也呈减小趋势,与本文试验结果一致。2.3 考虑原生各向异性的最大动剪切模量表征方法
图3中出现Gmax/F(e)随围压增大呈先上升后下降的特殊现象,文献[4]认为Gmax同时受到平均有效应力、孔隙比和结构损伤的影响,采用该文的表征方法对试验结果进行分析,具体的表达形式如下所示：
Gmax/F(e)=A(1+(σ′mpa)n)1+B(1+(σ′mpa)n)(kr+1−kr1+(ησ′mpc)λ)。 (5) 式中 A,B,n,kr,η和
λ 为反映各种应力历史和土体性质的参数；σ′m 为围压；pa为标准大气压；pc为表观前期固结压力即结构屈服应力σk ,不同方向试样压缩试验得到的σk 差异较小,均取400 kPa。采用式（5）将不同方向试样Gmax/F(e)与围压的关系进行定量表征。从图4可得,高应力下各向异性对试样的Gmax/F(e)影响减弱,可假定不同方向试样Gmax/F(e)极限值相同。最终将试验数据与拟合曲线一同绘制于图5,发现拟合效果很好,拟合参数见表2。
![]()
图 5 不同方向试样的Gmax/F(e)与固结围压lgσ3关系曲线Figure 5. Curves of Gmax/F(e) and confining pressure lgσ3 of specimens in different directions表 2 不同方向试样拟合参数Table 2. Fitting parameters of specimens in different directionsα A/MPa B n kr η λ R2 0° 39.92489 0.16678 0.54309 0.35092 0.56433 6.42998 0.99251 22.5° 37.89951 0.15999 0.58264 0.35462 0.56426 6.37147 0.99075 45° 33.76328 0.15168 0.54642 0.37740 0.55402 6.38473 0.99432 67.5° 31.15476 0.15761 0.56254 0.42499 0.60889 6.07737 0.99727 90° 29.75422 0.15743 0.56067 0.44448 0.57750 6.05669 0.99835 分析表2中拟合参数与试样方向的关系,可得参数A,kr,
λ 和试样轴线与土体沉积平面夹角α 呈线性关系（图6）,参数B,n,η随α 增大分别保持在0.1587,0.5591,0.5738上下,且波动范围较小（参数B,n,η的标准差S分别为0.005455,0.01570和0.02131）。![]()
图 6 拟合参数A,kr和λ与试样方向的关系Figure 6. Relationship between fitting parameters A, kr and λ with directions of specimens将图6中参数A,kr,
λ 的拟合方程和参数B,n,η的平均值同时代入式（5）,得到考虑原生各向异性的最大动剪切模量的表征方法：Gmax/F(e)=(c1α+c2)(1+(σ′mpa)n)1+B(1+(σ′mpa)n)· ((d1α+d2)+1−(d1α+d2)1+(ησ′mpc)(e1α+e2))。 (6) 式中
σ′m 为围压；α 表示试样的方向,为试样轴线与土体沉积平面夹角；pa为标准大气压,取101.325 kPa；pc为σk ,取400 kPa；B=0.1587,n=0.5591,η=0.5738；c1=−0.1204,c2=39.9166；d1=1.144×10−3,d2=0.3390；e1=−4.625×10−3,e2=6.4722。3. 结论
（1）在同一围压下,不同
α 试样经孔隙比函数归一化的最大动剪切模量Gmax/F(e)与90°方向试样Gmax/F(e)的比值Kα随α 增大而减小。当围压低于和高于σk 时,同一α 试样Kα随围压增长分别呈基本保持恒定与明显减小趋势,说明当围压低于σk 时,围压几乎不影响原生各向异性对Gmax影响,围压超过σk 后,不同方向的Gmax/F(e)差异减小,围压的增大减弱了原生各向异性对Gmax的影响。（2）受固结压硬和结构损伤的影响,湛江黏土的Gmax/F(e)变化规律与通常软黏土试验结果不同,不同方向试样的Gmax/F(e)随围压增大均呈先增大后减小规律,当围压在
σk 左右时出现转折。（3）基于采用考虑结构损伤的公式可很好拟合湛江黏土不同方向试样Gmax与围压关系曲线,提出了考虑原生各向异性影响的Gmax演化规律表征方法。
-
![]()
图 5 巷道围岩塑性区演化示意图
Figure 5. Evolution diagram of plastic zone of surrounding rock of roadways
![]()
图 7 蠕变前后煤体支承压力演化
Figure 7. Evolution of abutment pressure of coal mass before and after creep
![]()
图 10 孤立煤体蠕变后支承压力简化示意图
Figure 10. Simplified schematic diagram of abutment pressure after creep of isolated coal
![]()
图 13 不同开挖步数孤立煤体垂直应力曲线
Figure 13. Curves of vertical stress of isolated coal with different excavation steps
![]()
图 14 高应力厚煤层大巷孤立煤体冲击地压防治对策
Figure 14. Prevention and control countermeasures of rock burst of isolated coal in roadways of high-stress thick coal seam
-
[1] 姜鹏飞, 康红普, 王志根, 等. 千米深井软岩大巷围岩锚架充协同控制原理、技术及应用[J]. 煤炭学报, 2020, 45(3): 1020–1035. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB202003016.htm JIANG Peng-fei, KANG Hong-pu, WANG Zhi-gen, et al. Principle, technology and application of soft rock roadway strata control by means of "rock bolting, U-shaped yielding steel arches and back filling" in synergy in 1 000 m deep coal mines[J]. Journal of China Coal Society, 2020, 45(3): 1020–1035. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB202003016.htm
[2] 朱斯陶, 姜福兴, 刘金海, 等. 我国煤矿整体失稳型冲击地压类型、发生机理及防治[J]. 煤炭学报, 2020, 45(11): 3667–3677. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB202011003.htm ZHU Si-tao, JIANG Fu-xing, LIU Jin-hai, et al. Types, occurcenec mechanism and prevention of overall istability induced rockbursts in China coal mines[J]. Journal of China Coal Society, 2020, 45(11): 3667–3677. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB202011003.htm
[3] 孙守义, 赵长政, 张云, 等. 多煤层重复采动穿层大巷围岩变形特征及修复加固技术研究[J]. 采矿与安全工程学报, 2020, 37(4): 681–688. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL202004005.htm SUN Shou-yi, ZHAO Chang-zheng, ZHANG Yun, et al. The deformation characteristics of surrounding rock of crossing roadway in multiple seams under repeated mining and its repair and reinforcement technology[J]. Journal of Mining & Safety Engineering, 2020, 37(4): 681–688. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL202004005.htm
[4] 于洋, 柏建彪, 张树娟, 等. 双翼采动大巷群围岩灾变机理与修复加固体系研究[J]. 采矿与安全工程学报, 2020, 37(6): 1133–1141. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL202006007.htm YU Yang, BAI Jian-biao, ZHANG Shu-juan, et al. Disaster mechanism of surrounding rock with double wing mining roadway group and its repair and reinforcement system[J]. Journal of Mining & Safety Engineering, 2020, 37(6): 1133–1141. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL202006007.htm
[5] 高晓进, 李煜炜, 张振金, 等. 软岩巷道大变形双主动超前爆破预裂顶板防控技术[J]. 煤炭学报, 2020, 45(增刊2): 589–598. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2020S2006.htm GAO Xiao-jin, LI Yu-wei, ZHANG Zhen-jin, et al. Prevention and control technology of pre-splitting roof by dual active advanced blasting in soft rock large deformation roadway[J]. Journal of China Coal Society, 2020, 45(S2): 589–598. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2020S2006.htm
[6] 王高昂, 朱斯陶, 姜福兴, 等. 千米深井大巷孤立煤体整体失稳冲击机理及防治研究[J]. 采矿与安全工程学报, 2019, 36(5): 968–976. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201905015.htm WANG Gao-ang, ZHU Si-tao, JIANG Fu-xing, et al. Mechanism of rock burst induced by overall instability of isolated coal and its prevention in large well at thousands-kilometer underground[J]. Journal of Mining & Safety Engineering, 2019, 36(5): 968–976. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201905015.htm
[7] 潘俊锋, 刘少虹, 秦子晗, 等. 深部盘区巷道群集中静载荷型冲击地压机理与防治[J]. 煤炭学报, 2018, 43(10): 2679–2686. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201810003.htm PAN Jun-feng, LIU Shao-hong, QIN Zi-han, et al. Mechanism and prevention of concentrated static load type rock burst of roadway group in deep mining area[J]. Journal of China Coal Society, 2018, 43(10): 2679–2686. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201810003.htm
[8] 薛成春, 曹安业, 牛风卫, 等. 深部不规则孤岛煤柱区冲击地压机理及防治[J]. 采矿与安全工程学报, 2021, 38(3): 479–486. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL202103006.htm XUE Cheng-chun, CAO An-ye, NIU Feng-wei, et al. Mechanism and prevention of rock burst in deep irregular isolated coal pillar[J]. Journal of Mining & Safety Engineering, 2021, 38(3): 479–486. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL202103006.htm
[9] 孟庆彬, 孙稳, 韩立军, 等. 深井软岩巷道群掘进扰动效应与控制技术研究[J]. 采矿与安全工程学报, 2021, 38(3): 496-506. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL202103008.htm MENG Qing-bin, SUN Wen, HAN Li-jun, et al. Disturbing effect of excavation in deep soft rock roadways and control technology[J]. Journal of Mining & Safety Engineering, 2021, 38(3): 496–506. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL202103008.htm
[10] 刘帅, 杨科, 唐春安. 深井软岩下山巷道群非对称破坏机理与控制研究[J]. 采矿与安全工程学报, 2019, 36(3): 455–464. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201903004.htm LIU Shuai, YANG Ke, TANG Chun-an. Asymmetric failure mechanism and control of downhill roadway group of soft rock in deep mine[J]. Journal of Mining & Safety Engineering, 2019, 36(3): 455–464. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201903004.htm
[11] 尹万蕾, 潘一山, 李忠华, 等. 孤立煤柱非线性蠕变失稳滞后时间的研究[J]. 应用力学学报, 2016, 33(6): 1106–1112, 1126. https://www.cnki.com.cn/Article/CJFDTOTAL-YYLX201606028.htm YIN Wan-lei, PAN Yi-shan, LI Zhong-hua, et al. Lag time study on nonlinear creep buckling of the isolated coal pillar[J]. Chinese Journal of Applied Mechanics, 2016, 33(6): 1106–1112, 1126. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YYLX201606028.htm
[12] 刘金海, 郑学军, 刘虎, 等. 冲击地压矿井采区下山保护煤柱合理宽度研究[J]. 煤炭科学技术, 2021, 49(2): 52–60. https://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ202102007.htm LIU Jin-hai, ZHENG Xue-jun, LIU Hu, et al. Study on rational width of protective coal pillar for district dip in rock burst mine[J]. Coal Science and Technology, 2021, 49(2): 52–60. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ202102007.htm
[13] 陈国祥, 郭兵兵, 镐振. 圆形巷道围岩加速蠕变影响下冲击地压的启动条件[J]. 煤炭学报, 2020, 45(10): 3401–3407. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB202010004.htm CHEN Guo-xiang, GUO Bing-bing, HAO Zhen. Rockburst start-up condition influenced by accelerated creep of surrounding rock of circular roadway[J]. Journal of China Coal Society, 2020, 45(10): 3401–3407. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB202010004.htm
[14] 王青元, 刘杰, 王培涛, 等. 冲击扰动诱发蠕变岩石加速失稳破坏试验[J]. 岩土力学, 2020, 41(3): 781–788, 798. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202003008.htm WANG Qing-yuan, LIU Jie, WANG Pei-tao, et al. Experimental investigation of accelerated failure of creep rock induced by impact disturbance[J]. Rock and Soil Mechanics, 2020, 41(3): 781–788, 798. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202003008.htm
[15] 姜福兴, 冯宇, KOUAME K J A, 等. 高地应力特厚煤层"蠕变型"冲击机理研究[J]. 岩土工程学报, 2015, 37(10): 1762–1768. doi: 10.11779/CJGE201510003 JIANG Fu-xing, FENG Yu, KOUAME K J A, et al. Mechanism of creep-induced rock burst in extra-thick coal seam under high ground stress[J]. Chinese Journal of Geotechnical Engineering, 2015, 37(10): 1762–1768. (in Chinese) doi: 10.11779/CJGE201510003
[16] 经纬, 薛维培, 荣传新. 巷道(隧道)围岩稳定蠕变上下阈值及确定方法[J]. 煤炭学报, 2018, 43(10): 2718–2723. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201810008.htm JING Wei, XUE Wei-pei, RONG Chuan-xin. Stable creep upper and lower thresholds in roadway(tunnel) surrounding rock and it's determination method[J]. Journal of China Coal Society, 2018, 43(10): 2718–2723. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201810008.htm
[17] 杨光宇. 特厚煤层掘进巷道冲击地压分区防控研究[D]. 北京: 北京科技大学, 2019. YANG Guang-yu. Partition Prevention and Control of Rock Burst at the Headgate of Ultra-Thick Coal Seam[D]. Beijing: University of Science and Technology Beijing, 2019. (in Chinese)
[18] 赵阳升, 冯增朝, 万志军. 岩体动力破坏的最小能量原理[J]. 岩石力学与工程学报, 2003, 22(11): 1781–1783. doi: 10.3321/j.issn:1000-6915.2003.11.005 ZHAO Yang-sheng, FENG Zeng-chao, WAN Zhi-jun. Least energy priciple of dynamical failure of rock mass[J]. Chinese Journal of Rock Mechanics and Engineering, 2003, 22(11): 1781–1783. (in Chinese) doi: 10.3321/j.issn:1000-6915.2003.11.005
[19] 王保齐, 朱斯陶, 周涛, 等. 深井煤层大巷矿震发生机理及防治研究[J]. 煤炭技术, 2020, 39(3): 5–8. https://www.cnki.com.cn/Article/CJFDTOTAL-MTJS202003003.htm WANG Bao-qi, ZHU Si-tao, ZHOU Tao, et al. Study on mechanism and prevention of mine earthquakes in deep shaft main roadways[J]. Coal Technology, 2020, 39(3): 5–8. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-MTJS202003003.htm
下载:
计量
- 文章访问数: 180
- HTML全文浏览量: 34
- PDF下载量: 37
