Abstract
Due to inappropriate mining practices, water-conducting fracture zones can develop in an aquifer, not only destroying the surface-water environment but also causing water inrush, even hurting or killing workers. To avoid such disasters, investigating and simulating the evolution mechanism of water-conducting fractures are becoming a research focus in mining engineering, especially regarding the organisation and development of fractures. Our work mainly involved the design of low-strength analogous materials and the simulation of fracture evolution for weak-roof problems in shallow seam mining based on a self-built experimental hydromechanical coupling system. The experimental results show that the vertical stress in the roof increases first as the working face approaches and finally decreases to near its initial value as the working face passes. The relationship between fracture depth and coal-seam excavation distance is obviously nonlinear. The leakage velocity of surface water remains stable in the early stage of excavation and increases when the fracture develops through the main aquifuge. The maximum fracture depth is 76.18 m for the Yili coal mine with weak roofs and shallow coal seams. In addition, we numerically simulated and verified the evolution patterns with the FLAC3D platform. The simulated fracture depth of the Yili coal mine agreed with the in situ borehole observation very well and was more accurate than the output of the empirical formula. Our work provides new methods and relevant data for research on the evolution of water-conducting fractures in weak roofs during shallow seam mining.
Highlights
The development of water-conducting fracture zones in overlying strata is a common mining problem
Zhang [11] introduced a mechanism for water-conducting zone development and proposed improved measures in coal mining based on hydrogeological conditions
To predict and prevent water inrush during mining, it is necessary to ensure that the maximum height of the waterconducting fracture zone does not exceed the height between the coal seam and the aquifer
Summary
The development of water-conducting fracture zones in overlying strata is a common mining problem. Water movement analysis is essential to research on the mechanism behind water-conducting fracture zone development in overburden strata during mining. Many scholars have predicted the development of waterconducting fracture zones in coal mining [2,3,4,5,6,7,8,9,10]. Zhang [11] introduced a mechanism for water-conducting zone development and proposed improved measures in coal mining based on hydrogeological conditions. The impact factors for the development of a water-conducting fracture zone in a water-rich roof produced by long-span mining were analysed by Bai and Tu [13]. Majdi et al [14] predicted the evolution mechanism of the height of the distressed zone of a roof in long-wall mining
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
