Pore structure characterization and nonlinear seepage characteristics of rock mass in fault fracture zones

被引：0
|
作者：
Ma D. [1 ,2 ]
Li Q. [1 ]
Zhang J. [1 ,2 ]
Liu Y. [1 ]
Hou W. [1 ]
机构：
[1] School of Mines, China University of Mining and Technology, Xuzhou
[2] MOE Key Laboratory of Deep Coal Resource Mining, China University of Mining and Technology, Xuzhou
来源：
Meitan Xuebao/Journal of the China Coal Society | 2023年 / 48卷 / 02期
关键词：
fracture zone of faults; fractured rock; pore structure; prediction model; seepage characteristics;
D O I：
10.13225/j.cnki.jccs.S022.1678
中图分类号：
学科分类号：
摘要：
In order to reveal the mechanism of the occurrence of water inrush hazards in fault fracture zones in coal mining,it is necessary to study the pore structure characteristics and permeability of rock mass in fault fracture zones. A test device for fractured rock mass under coupled seepage and stress was developed. A method was proposed for determining the pore structure and hydraulic properties of fault rock mass under compression stress. The pore size distribution and nonlinear seepage behavior of fault rock mass affected by particle size distribution and stress were investigated. A permeability prediction model based on the nuclear magnetic resonance (NMR) was proposed. The experimental results show that ① the pore size distribution of both continuously graded and gap graded rock mass with a particle fractal dimension of 2.6 shows a three-peak structure,and the absence of small particles in graded rock mass leads to the increase of porosity and maximum pore size,which decreases the compressibility of the fault rock mass sample. ② The permeability of graded fractured rocks is dominated by the permeable porosity,and the bound porosity is less influenced by the stress. The increased stress and the absence of large particles lead to the decrease of permeability of fault rock mass sample. ③ The nonlinear seepage behaviors of both continuously graded and gap graded fault rock mass can be described by the Forchheimer equation,and the permeability and the β-factor of non-Darcy flow of fault rock mass vary in opposite trends under the influence of stress. The absence of small particles leads to a reduction in the β factor of graded fractured rock mass. ④ A NMR-based permeability prediction model for graded fault rock mass was proposed,which can significantly improve the accuracy of permeability prediction for graded fractured rock mass by removing the influence of bound pores and considering the weighted contribution of seepage pores. The results provide a scientific basis for revealing the mechanism of water inrush disaster and the prediction and prevention of water inrush disaster in coal mining. © 2023 China Coal Society. All rights reserved.
引用
收藏
页码：666 / 677
页数：11
相关论文
共 28 条
  • [1] WU Qiang, CUI Fangpeng, ZHAO Suqi, Et al., Type classification and main characteristics of mine water disasters [ J], Journal of China Coal Society, 38, 4, pp. 561-565, (2013)
  • [2] LI Shucai, PAN Dongdong, XU Zhenhao, Et al., A model test on catastrophic evolution process of water inrush of a concealed karst cave filled with confined water [ J], Rock and Soil Mechanics, 39, 9, pp. 3164-3173, (2018)
  • [3] LI Shucai, WANG Kang, LI Liping, Et al., Mechanical mechanism and development trend of water-inrush disasters in karst tunnels, Chinese Journal of Theoretical and Applied Mechanics, 49, 1, pp. 22-30, (2017)
  • [4] YANG Tianhong, SHI Wenhao, LIU Honglei, Et al., A non-linear flow model based on flow translation and its application in the mechanism analysis of water inrush through collapse pillar, Journal of China Coal Society, 42, 2, pp. 315-321, (2017)
  • [5] BARREE R D, CONWAY M W., Beyond beta factors:A complete model for darcy,forchheimer,and trans-forchheimer flow in porous media, Proceedings of the SPE Annual Technical Conference and Exhibition, (2004)
  • [6] YANG Tianhong, SHI Wenhao, LI Shuncai, Et al., State of the art and trends of water-inrush mechanism of nonlinear flow in fractured rock mass, Journal of China Coal Society, 41, 7, pp. 1598-1609, (2016)
  • [7] Dan MA, DUAN Hongyu, ZHANG Jixiong, Solid grain migration on hydraulic properties of fault rocks in underground mining tunnel:Radial seepage experiments and verification of permeability prediction [ J ], Tunnelling and Underground Space Technology, 126, (2022)
  • [8] MA Dan, DUAN Hongyu, ZHANG Jixiong, Et al., Experimental investigation of creep-erosion coupling mechanical properties of water inrush hazards in fault fracture rock masses, Chinese Journal of Rock Mechanics and Engineering, 40, 9, pp. 1751-1763, (2021)
  • [9] LI Shuncai, MIAO Xiexing, CHEN Zhanqing, Nonlinear dynamic analysis on non-Darcy seepage in over-broken rock mass, Journal of China Coal Society, 30, 5, pp. 15-19, (2005)
  • [10] ZHOU Nan, HAN Xiaole, ZHANG Jixiong, Et al., Compressive deformation and energy dissipation of crushed coal gangue [ J ], Powder Technology, 297, pp. 220-228, (2016)
123