采场覆岩变形和来压判别的分布式光纤监测模型试验

为了研究煤矿工作面开采过程中，上覆岩层变形规律，将分布式光纤传感技术(BOTDA)应用于三维立体模型试验监测。制作了3 600 mm×2 000 mm×2 000 mm(长×宽×高)三维立体模型同时在模型内部预埋3根垂直光纤，模拟工作面的开采，工作面共开挖60次，累计推进2 400 mm，获得3根分布式光纤的180组布里渊(Brillouin)频移试验数据。提出了分布式光纤频移平均变化度的概念，采用光纤频移来表征采场上覆岩层变形垮落，判别工作面初次来压和周期来压情况;并将其测试结果和内部位移测试结果进行对比。结果表明，光纤频移平均变化度可以反映工作面上覆岩层变形、来压及其变化情况，该方法及其技术推广应用可以为上覆岩层变形信息化提供依据。

Model test for evaluating deformation and weighting of overlying strata by distributed optical fiber sensing

To examine the deformation law of overlying strata in the excavation of the working face,BOTDA is applied to the three-dimensional model test.The three-dimensional model,internally embedded with three vertical optical fibers,which measures 3 600 mm (L)by 2 000 mm (W)by 2 000 mm (H),simulates the excavation of the working face 60 times with a cumulative advance of 2 400 mm.And 180 groups of Brillouin frequency shift test data of the three-distributed optical fibers are obtained.The concept of average variation of distributed optical fiber frequency shift is proposed to evaluate the initial weighting and period weighting in the working face,and the optical fiber frequency shift is used to characterize the deformation and collapse of the overlying strata.A comparison is made on the test results with those of the internal displacement indicating that the average variation of the distributed optical fiber frequency shift is an accurate reflection of the deformation,pressure and changes of the overlying strata,and that the popularization and application of this technology may provide a reliable basis for intelligent mining in the future.