采用分布式光纤传感技术的煤矿顶板变形实验研究

Experimental study on deformation of coal mine roof using distributed optical fiber sensing technology

为研究分布式光纤传感监测技术和传统监测手段的差异以及煤矿开采过程中顶板变形规律,将分布式光纤传感技术(BOTDR)和沉降量多点测量系统应用于煤矿顶板模型实验中进行形变监测研究.制作长为1500 mm、宽为1000 mm、高为1000 mm的类煤矿顶板模型并通过模拟煤矿开采过程进行频移监测实验和沉降量监测实验.提出频移相对变化度和沉降量平均变化度,通过频移和应变关系用频移相对变化度表征形变程度,模拟实验中顶板可监测形变为沉降形变,通过对光纤频移的监测和应变关系得到顶板形变量,并与多点沉降仪监测到的沉降量相对变化度对比.研究结果表明:两者的变化基本一致且频移监测效果更明显,验证了分布式光纤传感技术用于监测顶板变形的可行性与可靠性.

In order to study the effect contrast between distributed optical fiber sensor monitoring technology and traditional monitoring methods and the rule of roof deformation in the process of coal mining,distributed optical fiber sensor technology(BOTDR)and multi-point measuring system were applied to coal mine roof model experiments for deformation monitoring study.By making a model of the coal mine roof with 1500 mm×1000 mm×1000 mm(length×width×height),the frequency shift monitoring experiment and multi-point measuring system for settlement amount experiment are carried out by simulating the whole coal mining process.The relative variation of frequency shift and average variation of settlement amount are put forward,and the degree of deformation is characterized by the relative variation of frequency shift through the relations between frequency shift and strain.In this simulation experiment,the roof deformation that can be monitored is settlement deformation.By comparing the variation of roof deformation,which can be obtained from monitoring optical fiber frequency shift and its relations with strain,with the relative variation of settlement amount monitored by multi-point measuring system,the result shows the variation obtained from the two methods are consistent while the effect of frequency shift monitoring is more obvious,which verifies the feasibility and reliability of distributed optical fiber sensor technology using in monitoring roof deformation.