采场覆岩变形分布式光纤测量研究

摘要

为了研究分布式光纤传感技术在采场相似材料模拟试验检测中的适用性,将BOTDA和PPP-BOTDA两种分布式光纤传感技术应用于采场相似材料模拟试验覆岩移动变形的测量.在模型内水平埋设2根传感光纤用于检测岩层变形,试验分2个阶段进行,分别采用不同的分布式光纤传感技术测量岩层移动变形,并将二者的测量结果与岩层移动状态、百分表、全站仪、岩层垮落宽度进行了对比分析.试验表明,分布式光纤传感技术能够实现采场相似材料模拟试验的分布式测量,其结果能和岩层移动状态、百分表、全站仪良好对应,岩层垮落宽度测量准确;仪器空间分辨率直接影响模型试验测量结果准确性,具备高空间分辨率的PPP-BOTDA分布式光纤传感技术更适用于相似材料模拟试验的分布式测量.%In order to study the applicability of distributed optical fiber sensing technology in similar material model experiment detection,BOTDA and PPP-BOTDA distributed optical fiber sensing technology are applied to measure overlying strata deformation of similar material model.Two sensing fibers are embedded horizontally in model to detect overburden deformation.The test is carried out in two stages,and two kinds of distributed optical fiber sensing technology are used to measure deformation of rock strata,and measured results are contrasted with overlying strata movement status,dial indicator,total station and rock collapse width.The results showed that distributed optical fiber sensing technology achieved distributed measurement of similar material simulation experiment,optical fiber measurement results and overlying strata movement status,dial indicator,total station measurement results had good corresponding relationship,measuring rock collapse width was accurate.The spatial resolution directly influences accuracy of the model test results;PPP-BOTDA distributed optical fiber sensing technology with high spatial resolution is more suitable for the distributed measurement of similar material model experiment.