Shi Longqing, Qu Xingyue, Qiu Mei, Han Jin, Zhang Weiqiang
College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, China.
College of Computer Science and Engineering, Shandong University of Science and Technology, Qingdao, China.
PLoS One. 2024 Mar 12;19(3):e0298399. doi: 10.1371/journal.pone.0298399. eCollection 2024.
When Chinese coal mines are mining Carboniferous Permian coal seams, the mechanism of water inrush from the roof of the working face usually conforms to the "Upper Three Zones" or "Upper Four Zones" theory. The water inrush passageway is water-conducting fracture zone, and the water inrush position is located in the goaf. However, when mining Jurassic coal seams in Chinese coal mines, the location of water inrush often appears at the head-on working face, above the coal mining machine. Due to the support of the fully mechanized mining support, the roof rock layer cannot collapse and therefore cannot form water-conducting fracture zone. Therefore, the water inrush mechanism cannot be explained by the above two theories. This paper is guided by the Practical Mine Pressure Control Theory, and based on the explanation of the motion forms of bending (pulling) failure movement and shearing (cutting) failure movement, and combined with on-site examples, it is revealed that the passageways leading to from the head-on working face roof in a Jurassic coal seam in the Ordos Basin are splitting zones type, fracture line type and structural fracture type, respectively. Taking the changes in water inflow during the mining process of the 3301 and 3302 working faces in Zhujiamao Coal Mine as examples, this paper reveals the mechanism of water inrush from the head-on working face roof caused by splitting zones type, and proves the existence of this passageway through on-site 3D high-density electrical detection and tracing experiments. Taking two catastrophic water inrush accidents that occurred head-on in the 1309 working face of Guojiahe Coal Industry Co., Ltd. as examples, the water inrush mechanism of the fracture line type and the water inrush mechanism of the structural fracture type were respectively revealed. Based on mechanism of water inrush from head-on roof of working face and the analysis of the on-site water inrush process, a method for distinguishing the type of water inrush passageway from the front roof of the working face is proposed. The results indicate that the Jurassic coal seam mining in the Ordos Basin is prone to shearing (cutting) failure movement, resulting in the frequent formation of the three types of water inrush passageways mentioned above.
中国煤矿在开采石炭二叠纪煤层时，工作面顶板突水机理通常符合“上三带”或“上四带”理论。突水通道为导水裂隙带，突水位置位于采空区。然而，中国煤矿在开采侏罗纪煤层时，突水位置常出现在迎头工作面采煤机上方。由于综采支架的支撑，顶板岩层无法垮落，因此无法形成导水裂隙带。所以，上述两种理论无法解释突水机理。本文以实用矿山压力控制理论为指导，在阐释弯曲（拉伸）破坏运动和剪切（切割）破坏运动的运动形式的基础上，结合现场实例，揭示了鄂尔多斯盆地某侏罗纪煤层迎头工作面顶板形成的突水通道分别为离层带型、断裂线型和构造裂隙型。以朱家峁煤矿3301和3302工作面开采过程中的涌水量变化为例，揭示了离层带型导致迎头工作面顶板突水的机理，并通过现场三维高密度电法探测及追踪试验验证了该通道的存在。以郭家滩煤业有限公司1309工作面迎头发生的两起特大突水事故为例，分别揭示了断裂线型突水机理和构造裂隙型突水机理。基于工作面迎头顶板突水机理及现场突水过程分析，提出了一种判别工作面迎头顶板突水通道类型的方法。结果表明，鄂尔多斯盆地侏罗纪煤层开采易发生剪切（切割）破坏运动，导致上述三种突水通道频繁形成。
