Deformations and seepage-induced erosion of fractured rocks in fault under confined settings

Authors

SUN Wenbin, Shaanxi Key Laboratory of Prevention and Control Technology for Coal Mine Water Hazard, Xi’an 710077, China; College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao 266590, ChinaFollow
TIAN Dianjin, College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao 266590, ChinaFollow
MA Cheng, College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao 266590, China
XUE Yanchao, College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao 266590, China
YANG Can, College of Energy and Mining Engineering, Shandong University of Science and Technology, Qingdao 266590, China
ZHU Kaipeng, Shaanxi Key Laboratory of Prevention and Control Technology for Coal Mine Water Hazard, Xi’an 710077, China

Abstract

Objective Most of the mining areas in China have entered the deep mining stage. In this case, the risks of mine water inrushes increase significantly due to the complex deep hydrogeological conditions, a significant increase in the number of hidden disaster-causing factors, and the existence of faults. Methods Using a deformation-seepage experiment system for fractured rocks, this study investigated the characteristics of compressive deformations and seepage-induced erosion of fractured rocks in faults. By analyzing the impacts of particle-size distribution combinations, saturation state, and seepage pressure, on the deformation-permeability characteristics of fractured rocks under confined axial compression, this study investigated the time-varying patterns of changes in the particle erosion characteristics, void structure, and seepage parameters of the fractured rock samples. Results and Conclusions The results indicate that the peak strain of the fractured rock samples increased with an increase in the Talbot index (n). For samples with the same particle size distribution, those in the water-saturated state exhibited higher incremental strain than those in the dry state. The fitted curves of the lost mass of particles exhibited an exponential growth function with time, with the lost mass being inversely proportional to the confining axial stress. Meanwhile, the mass of secondary particles increased with the axial load. The evolutionary trend of the void rate of the rock samples was closely related to their particle size distributions, with the Talbot index (n) correlating positively with the overall void rate of the samples. Comparison before and after loading and seepage revealed that the fractal dimension (D) was inversely proportional to the value of n and the masses of fine and coarse particles increased and decreased, respectively. Furthermore, the fractal dimension of the rock samples increased significantly after loading and seepage. Macroscopically, the confined water lift within faults can be divided into the initial stage of water lift, the expansion stage of channels for discharging water and sand inrush, and the mature stage of the channels. Microscopically, the lift involves the soaking and softening, dislocation and compression, deformations and cracking, and fragmentation and detachment of rock masses. The findings of this study will provide experimental data and a theoretical basis for research on the evolutionary patterns of water inrush disasters in faults.

Keywords

fractured fault zone, particle loss, void structure, fractal characteristic, deformation pattern, water inrush in fault

DOI

10.12363/issn.1001-1986.24.05.0333

Recommended Citation

SUN Wenbin, TIAN Dianjin, MA Cheng, et al. (2025) "Deformations and seepage-induced erosion of fractured rocks in fault under confined settings," Coal Geology & Exploration: Vol. 53: Iss. 1, Article 16.
DOI: 10.12363/issn.1001-1986.24.05.0333
Available at: https://cge.researchcommons.org/journal/vol53/iss1/16

Reference

[1] 武强，郭小铭，边凯，等. 开展水害致灾因素普查 防范煤矿水害事故发生[J]. 中国煤炭，2023，49(1)：3−15.

WU Qiang，GUO Xiaoming，BIAN Kai，et al. Carrying out general survey of the water disaster-causing factors to prevent the occurrence of coal mine water disasters[J]. China Coal，2023，49(1)：3−15.

[2] 边凯，李思宇，刘博，等. 承压水上含断层煤层开采底板突水规律研究[J]. 煤矿安全，2022，53(6)：169−177.

BIAN Kai，LI Siyu，LIU Bo，et al. Study on water inrush law of mining floor in coal seam with fault above confined water[J]. Safety in Coal Mines，2022，53(6)：169−177.

[3] 孙文斌，杨辉，赵金海，等. 断层突水灾变演化过程划分基础试验研究[J]. 煤炭科学技术，2023，51(7)：118−128.

SUN Wenbin，YANG Hui，ZHAO Jinhai，et al. Basic experimental research on the delineation of the evolutionary process of fault water inrush[J]. Coal Science and Technology，2023，51(7)：118−128.

[4] 缪协兴，钱鸣高. 中国煤炭资源绿色开采研究现状与展望[J]. 采矿与安全工程学报，2009，26(1)：1−14.

MIAO Xiexing，QIAN Minggao. Research on green mining of coal resources in China：Current status and future prospects[J]. Journal of Mining & Safety Engineering，2009，26(1)：1−14.

[5] WANG Luzhen，KONG Hailing. Variation characteristics of mass-loss rate in dynamic seepage system of the broken rocks[J]. Geofluids，2018，2018(1)：7137601.

[6] FENG Meimei，WU Jiangyu，MA Dan，et al. Experimental investigation on the seepage property of saturated broken red sandstone of continuous gradation[J]. Bulletin of Engineering Geology and the Environment，2018，77(3)：1167−1178.

[7] LEPS T M. Flow through rock fill[M]. New York：Wiley-Inter Science，Div of John Wiley & Sons. Inc.，1973.

[8] LIU Weiqun，FEI Xiaodong，FANG Jingnian. Rules for confidence intervals of permeability coefficients for water flow in over-broken rock mass[J]. International Journal of Mining Science and Technology，2012，22(1)：29−33.

[9] RICHARDS K S，REDDY K R. Critical appraisal of piping phenomena in earth dams[J]. Bulletin of Engineering Geology and the Environment，2007，66(4)：381−402.

[10] RANJITH P G，PERERA M S A，PERERA W K G，et al. Sand production during the extrusion of hydrocarbons from geological formations：A review[J]. Journal of Petroleum Science and Engineering，2014，124：72−82.

[11] 李樯，马丹，张吉雄，等. 断层带破碎岩体采动剪切变形与渗透性演化规律[J]. 煤田地质与勘探，2023，51(8)：150−160.

LI Qiang，MA Dan，ZHANG Jixiong，et al. Mining-induced shear deformation and permeability evolution law of crushed rock mass in fault zone[J]. Coal Geology & Exploration，2023，51(8)：150−160.

[12] 陈家瑞，浦海，肖成，等. 变形历程对破碎岩体水沙渗流特性影响试验研究[J]. 采矿与安全工程学报，2016，33(2)：329−335.

CHEN Jiarui，PU Hai，XIAO Cheng，et al. Experimental study of impact of deformation history on water-sand seepage characteristics of broken rock[J]. Journal of Mining & Safety Engineering，2016，33(2)：329−335.

[13] 姚邦华. 破碎岩体变质量流固耦合动力学理论及应用研究[D]. 徐州：中国矿业大学，2012.

YAO Banghua. Research on variable mass fluid-solid coupling dynamics theory of broken rockmass and application[D]. Xuzhou：China University of Mining and Technology，2012.

[14] 姚邦华，茅献彪，魏建平，等. 考虑颗粒迁移的陷落柱流固耦合动力学模型研究[J]. 中国矿业大学学报，2014，43(1)：30−35.

YAO Banghua，MAO Xianbiao，WEI Jianping，et al. Study on coupled fluid-solid model for collapse columns considering the effect of particle transport[J]. Journal of China University of Mining & Technology，2014，43(1)：30−35.

[15] 姚邦华，王连成，魏建平，等. 煤矿陷落柱突水的变形–渗流–冲蚀耦合模型及应用[J]. 煤炭学报，2018，43(7)：2007−2013.

YAO Banghua，WANG Liancheng，WEI Jianping，et al. A deformation-seepage-erosion coupling model for water outburst of karst collapse pillar and its application[J]. Journal of China Coal Society，2018，43(7)：2007−2013.

[16] 张天军，张秀锋，庞明坤，等. 颗粒流失对陷落柱充填物孔隙结构及突水行为的影响[J]. 煤炭学报，2021，46(10)：3245−3254.

ZHANG Tianjun，ZHANG Xiufeng，PANG Mingkun，et al. Effect of particle loss on the pore structure and emergent behavior of karst column fills[J]. Journal of China Coal Society，2021，46(10)：3245−3254.

[17] 黄昌富，张帅龙，高永涛，等. 三轴应力下颗粒流失对断层破碎带凝灰岩渗流特征的影响[J]. 工程科学学报，2022，44(7)：1134−1146.

HUANG Changfu，ZHANG Shuailong，GAO Yongtao，et al. Influence of particle loss on the seepage characteristics of tuff in the fault fracture zone under triaxial stress[J]. Chinese Journal of Engineering，2022，44(7)：1134−1146.

[18] 王路珍. 变质量破碎泥岩渗透性的加速试验研究[D]. 徐州：中国矿业大学，2014.

WANG Luzhen. Accelerated experimental study on permeability for broken mudstone with mass loss[D]. Xuzhou：China University of Mining and Technology，2014.

[19] YU Bangyong，CHEN Zhanqing，WU Jiangyu. Experimental investigation on seepage stability of filling material of karst collapse pillar in mining engineering[J]. Advances in Civil Engineering，2018，2018：3986490.

[20] 刘伟韬，杜衍辉，于师建，等. 陷落柱骨架砂岩三轴压缩渗流特性及声发射特征试验研究[J]. 岩石力学与工程学报，2021，40(8)：1580−1590.

LIU Weitao，DU Yanhui，YU Shijian，et al. Research on permeability and acoustic emission characteristics of karst collapsed column skeleton sandstone under triaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2021，40(8)：1580−1590.

[21] 张培森，孙亚楠，颜伟，等. 饱和破碎砂岩承压变形及渗流特性试验研究[J]. 采矿与安全工程学报，2019，36(5)：1016−1024.

ZHANG Peisen，SUN Yanan，YAN Wei，et al. Experimental study on pressure deformation and seepage characteristics of saturated crushed rock[J]. Journal of Mining & Safety Engineering，2019，36(5)：1016−1024.

[22] 孙亚楠，张培森，颜伟，等. 采空区破碎砂岩承压变形特性试验研究[J]. 煤炭科学技术，2019，47(12)：56−61.

SUN Yanan，ZHANG Peisen，YAN Wei，et al. Experimental study on pressure-bearing deformation characteristics of crushed sandstone in gob[J]. Coal Science and Technology，2019，47(12)：56−61.

[23] 王伟，徐卫亚，王如宾，等. 低渗透岩石三轴压缩过程中的渗透性研究[J]. 岩石力学与工程学报，2015，34(1)：40−47.

WANG Wei，XU Weiya，WANG Rubin，et al. Permeability of dense rock under triaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering，2015，34(1)：40−47.

[24] 张俊文，王海龙，陈绍杰，等. 大粒径破碎岩石承压变形特性[J]. 煤炭学报，2018，43(4)：1000−1007.

ZHANG Junwen，WANG Hailong，CHEN Shaojie，et al. Bearing deformation characteristics of large-size broken rock[J]. Journal of China Coal Society，2018，43(4)：1000−1007.

[25] 张超，展旭财，杨春和. 粗粒料强度及变形特性的细观模拟[J]. 岩土力学，2013，34(7)：2077−2083.

ZHANG Chao，ZHAN Xucai，YANG Chunhe. Mesoscopic simulation of strength and deformation characteristics of coarse grained materials[J]. Rock and Soil Mechanics，2013，34(7)：2077−2083.

[26] 谢和平. 分形–岩石力学导论[M]. 北京：科学出版社，1996.

[27] 王昌祥. 采空区空隙分布规律及注浆加固治理[D]. 青岛：山东科技大学，2017.

WANG Changxiang. Mining voids distribution and grouting reinforcement treatment[D]. Qingdao：Shandong University of Science and Technology，2017.

[28] 王路珍，孔海陵. 伴随质量流失的破碎岩石渗透性的加速试验研究[M]. 北京：科学出版社，2017.

[29] 马占国，郭广礼，陈荣华，等. 饱和破碎岩石压实变形特性的试验研究[J]. 岩石力学与工程学报，2005，24(7)：1139−1144.

MA Zhanguo，GUO Guangli，CHEN Ronghua，et al. An experimental study on the compaction of water-saturated over-broken rock[J]. Chinese Journal of Rock Mechanics and Engineering，2005，24(7)：1139−1144.

[30] 梁彦波，江宁，赵金海，等. 采空区破碎岩石承压变形及分形特征研究[J]. 矿业研究与开发，2019，39(5)：60−64.

LIANG Yanbo，JIANG Ning，ZHAO Jinhai，et al. Study on compressive deformation and fractal characteristics of broken rocks in goaf[J]. Mining Research and Development，2019，39(5)：60−64.

[31] 陆银龙，王连国. 含断层煤层底板损伤破坏演化数值模拟及微震监测研究[J]. 采矿与安全工程学报，2013，30(1)：38−44.

LU Yinlong，WANG Lianguo. Modeling and microseismic monitoring of damage and failure evolution of faulty coal seam floor[J]. Journal of Mining & Safety Engineering，2013，30(1)：38−44.

[32] LI Wenping，WANG Qiqing，LIU Shiliang，et al. Study on the creep permeability of mining-cracked N₂ laterite as the key aquifuge for preserving water resources in northwestern China[J]. International Journal of Coal Science & Technology，2018，5(3)：315−327.