采动覆岩变形分布式光纤物理模型试验研究

摘要

采动覆岩变形破坏对开采巷道的安全构成威胁,同时易造成地面塌陷,对地面构筑物的安全和地质环境产生影响.因此,对煤层采动覆岩变形进行监控,具有重要的现实意义.论文针对煤层采动覆岩变形破坏的一般规律,利用分布式光纤感测技术,开展了采动覆岩变形物理模型试验研究.采用将感测光缆竖直植入物理模型内部的布设方法,获得了煤层采动过程中覆岩变形分布式监测结果.将光纤测试结果与常规近景摄影结果进行对比,结果基本吻合;同时,揭示了采动覆岩变形破坏规律和覆岩离层的演化过程.利用经验公式计算得出“导高”均值约为30.6cm,这与光纤监测数据分析估算得到的30cm基本一致.试验结果表明:将分布式光纤感测技术引入采动覆岩破坏模型试验是可行且准确的,为以后的相关研究提供了一种新的思路与方法.%Deformation and failure of overlying rock strata during coal mining poses a threat to the safety of mining roadway,can cause land subsidence,and can affect the safety of the buildings on the ground surface and the geological environments.Therefore,it is of great significance to carry out real-time deformation monitoring of overlying strata during coal mining.In this paper,the deformation and failure mechanism of overlying strata in coal seam is investigated through laboratory model test.The distributed fiber optic sensing technique is used.The fiber optic cables are vertically buried in the model to form a fiber optic monitoring system for measuring distributed deformation information.The fiber optic test results are consistent with the results of conventional photogrammetry system.They reveal the deformation mechanism and evolution process of the overlying rock mass during coal mining.It is found that using empirical formula,the height of water flowing fractured zone is calculated to be about 30.6cm,which fits well with the fiber optic estimated results of 30cm.The test results show that the application of distributed fiber optic sensing technology to the model test on mining-induced damage of overlying strata is feasible and accurate,which provides a new method for relevant research in the future.