刘奇,牛家宝,李青海,等. 采动覆岩裂隙演化的光纤监测耦合性及分带表征[J]. 煤炭学报,2024,49(3):1345−1357. DOI: 10.13225/j.cnki.jccs.2023.1282
引用本文: 刘奇,牛家宝,李青海,等. 采动覆岩裂隙演化的光纤监测耦合性及分带表征[J]. 煤炭学报,2024,49(3):1345−1357. DOI: 10.13225/j.cnki.jccs.2023.1282
LIU Qi,NIU Jiabao,LI Qinghai,et al. Deformation zoning characterization of mining rock mass based on partition coupling optical fiber sensing[J]. Journal of China Coal Society,2024,49(3):1345−1357. DOI: 10.13225/j.cnki.jccs.2023.1282
Citation: LIU Qi,NIU Jiabao,LI Qinghai,et al. Deformation zoning characterization of mining rock mass based on partition coupling optical fiber sensing[J]. Journal of China Coal Society,2024,49(3):1345−1357. DOI: 10.13225/j.cnki.jccs.2023.1282

采动覆岩裂隙演化的光纤监测耦合性及分带表征

Deformation zoning characterization of mining rock mass based on partition coupling optical fiber sensing

  • 摘要: 分布式光纤感测作为科学认识采动覆岩动态演变规律的重要工具,其监测数据的准确性主要取决于光纤−岩体的耦合关系。选择神东某矿作为研究对象,将分布式光纤感测技术应用于相似模拟实验,结合光纤−岩体耦合关系,探究采动覆岩垂直分带时空演化特征与光纤应变数据峰值点位置的内在联系。针对以往研究中光纤应变数据容易受光纤−岩体耦合关系影响,从而导致测试结果出现误差的问题,提出用岩体裂隙率表征光纤−岩体耦合关系的新方法。通过光纤−岩体耦合关系试验,得到光纤−岩体应变传递系数与岩体裂隙率之间呈线性函数关系,并采用二值化方法处理模型图像获取各区域裂隙变化量,分区域地计算出采动覆岩直埋光纤的应变传递系数,为进一步探究光纤应变数据峰值与采动覆岩垂直分带特征之间的关系提供了支撑。研究表明:光纤应变峰值点位置能用于关键层下方离层以及覆岩分带表征,利用构建的关键层下方离层及覆岩分带表征模型,结合峰值检测算法,得到关键层的位置分别为44、68、107 cm,以及垮落带、导水裂隙带发育高度分别为35、68 cm,算法识别结果与理论计算数值吻合,符合神东某矿的实际情况。

     

    Abstract: Distributed optical fiber sensing is an important tool for understanding the dynamic evolution of mining rock movement, and the accuracy of monitoring data mainly depends on the fiber-rock coupling relationship. In this study, the 22207 working face of the Buertai Coal Mine in the Shenmu Mining Area was selected as the research object. The distributed optical fiber sensing technology was applied to similarity model tests, combined with the fiber-rock coupling relationship, to explore the inherent connection between the spatiotemporal evolution characteristics of mining-induced overlying strata vertical zoning and the peak strain data locations along the optical fiber. To address the issue of measurement errors caused by the influence of the fiber-rock coupling relationship on the strain data, a new method was proposed to characterize the fiber-rock coupling relationship using the percentage of fissures in the rock mass. Through the experiments on the fiber-rock coupling relationship, a linear function relationship between the fiber-rock strain transmission coefficient and the percentage of fissures in the rock mass was obtained. The binary method was used to process the model images and obtain the variation of fissures in each region. The strain transmission coefficients of the buried optical fiber in the mining-induced overlying strata were calculated in different zones, providing support for further exploring the relationship between the peak strain data and the vertical zoning characteristics of mining-induced overlying strata. The study showed that the peak strain data locations along the optical fiber can be used to characterize the key stratum position below and the zoning of the overlying strata. A model representing the key stratum position below and the zoning of the overlying strata was constructed. By using the peak detection algorithm, the positions of the key stratum were identified as 44, 68, and 107 cm, and the development heights of the falling zone and the water flowing fractured zone were determined to be 35 cm and 68 cm, respectively. The algorithm's identification results were consistent with the theoretically calculated values, and they were in line with the actual situation of the 22207 working face. The research findings have improved the accuracy of distributed optical fiber sensing technology in the field of monitoring dynamic deformation of mining rock, providing new research ideas for characterizing key stratum positions and rock zoning.

     

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