基于光纤光栅传感技术的覆岩变形演化规律试验研究

Model Test of Overburden Deformation Evolution Based on Fiber Bragg Grating Sensing Technology

为了研究采场覆岩变形和采动压力变化的规律,文章以榆神矿区杭来湾煤矿的地质条件为背景,在实验室搭建3000 mm×200 mm×1150 mm物理相似材料模型进行模拟试验,模型中埋设4个光纤光栅传感器,用于实时监测覆岩关键层移动变形和采动支承压力变化的情况。结果表明,光纤光栅传感器位于工作面前方时,其应变曲线与工作面的支承压力有较好的一一对应线性关系;位于工作面后方时,其应变曲线呈波谷状时,而工作面的支承压力呈波峰状,且随着覆岩高度的增大,出现水平错位的现象。结论表明,光纤Bragg光栅传感监测技术在模型试验覆岩关键层内部应变和采动支承压力监测中具有良好的适用性,可为模型试验提供新的监测方法与手段。

In order to study the law of overburden deformation and mining pressure change in stope.Taking the geological conditions of Hanglaiwan Coal Mine in Yushen Mining Area as the background,it was built in the laboratory 3000 mm×1340 mm×200 mm physical similar material model is used for simulation test,four Fiber Bragg Grating Sensors are embedded in the model to monitor the movement and deformation of key overburden layers and the change of mining bearing pressure in real time.Then,the influencing factors and strain transfer coefficients of fiber bragg grating are determined through theoretical analysis and calibration experiments.The results show that:when the fiber bragg grating sensor is located in the front of the working face,its strain curve has a good one-to-one linear relationship with the supporting pressure of the working face.When it is located behind the working face,the strain curve is in the shape of trough,while the bearing pressure of the working face is in the shape of crest,and the phenomenon of horizontal dislocation occurs with the increase of overburden height.The conclusion shows that the Fiber Bragg Grating Sensing monitoring technology has good applicability in the monitoring of internal strain and mining bearing pressure of key overburden layers in model test,and can provide a new monitoring method and means for model test.