The height of water-conducting fracture zones (WCFZs) is vital for the prevention of water, gas, and roof accidents in coal mines. However, its dynamic evolution law and maximum height are difficult to be obtained by traditional prediction methods, especially for conditions in which there is high overburden caving strength and a thick coal seam. Therefore, taking the 150,313 fully mechanized caving working face in Yingying Coal Mine as a background, according to the principle of optimized processes, a new predicting approach based on the Brillouin optical time-domain reflectometry (BOTDR) is proposed. Firstly, we estimated the height through empirical formula calculation, theoretical analysis, and similar model simulation tests. Secondly, we studied the optimized layout of optical cables in the overburden in detail for predicting the maximum height of the WCFZ and keeping the cables in good performance during field prediction. Thirdly, we researched and optimized the borehole parameters, optical fiber selection, and the special protection measures. Finally, we applied the aforementioned optimized outcomes in the field experiment to dynamically predict the height of the WCFZ. As a result of the field experiment, the distribution characteristics of optical fiber strain, the maximum height, and the evolution law of the WCFZ were obtained through the regular monitoring of fiber strain using BOTDR. The experiment demonstrated that its maximum height is consistent with the results studied indoors. The validation and feasibility of the approach proposed in this paper were verified via the aforementioned studies. The research in this paper has good reference value and important significance for predicting the height of the WCFZ using BOTDR in coal mines with similar geological and productive conditions.

中文翻译：

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基于优化过程的高覆岩崩落强度下导水裂隙带高度预测的新方法

导水裂缝带（WCFZs）的高度对于预防煤矿中的水，气和顶板事故至关重要。但是，传统的预测方法很难获得其动态演化规律和最大高度，特别是在上覆崩落强度高，煤层厚的条件下。因此，以盈鹰煤矿150313综放工作面为背景，根据优化工艺原理，提出了一种基于布里渊光时域反射仪（BOTDR）的新预测方法。首先，我们通过经验公式计算，理论分析和类似的模型模拟测试来估算高度。其次，我们详细研究了覆盖层中光缆的优化布局，以预测WCFZ的最大高度并在现场预测期间保持光缆的良好性能。第三，研究和优化了井眼参数，光纤选择和特殊保护措施。最后，我们在野外实验中应用了上述优化结果，以动态预测WCFZ的高度。现场试验的结果是，通过使用BOTDR定期监测光纤应变，获得了WCFZ的光纤应变分布特性，最大高度和演化规律。实验表明，其最大高度与室内研究结果一致。通过上述研究验证了本文提出的方法的有效性和可行性。本文的研究对于地质条件和生产条件相近的煤矿利用BOTDR预测WCFZ高度具有重要的参考价值和重要意义。