基于光纤Bragg光栅的采动支承压力分布试验研究

Experimental study on mining-induced abutment pressure distribution pattern based on FBG sensor

为了研究采动支承压力的分布情况,采用光纤Bragg光栅(FBG)传感器对长壁采场模型试验进行了测试,在模型中埋设了9支FBG应变传感器,对比分析工作面推进时底板支承压力与上位FBG的测试结果。试验揭示了FBG测试结果与支承压力变化呈现镜面反射,在超前支承压力影响范围内支承压力与波长漂移呈线性关系。研究提出了支承压力FBG测试灵敏度参数,其表征了FBG传感器每变化1 pm时的支承压力变化;定量分析了围岩采动支承压力分布规律,得出了测线2三支FBG所在层位的支承压力大小与影响范围(K,L1,L2),同时建立了基于FBG的围岩采动支承压力的分布模型,用于描述采动围岩体中支承压力在不同层位和距离工作面不同距离时的分布规律。

In order to study the mining-induced abutment pressure distribution pattern,a model test of long wall mining stope was established with the optical fiber Bragg grating（ FBG） sensing technique,and nine FBG sensors and electrical pressure sensors were deployed in the model to contrastively analyze the change of wavelength shifts of FBG and the abutment pressure variation. The experiment results show that the wavelength shift and the abutment pressure present a specular reflection and the abutment pressure has a liner relation with FBG wavelength shift. We propose and define the FBG monitoring sensitivity of abutment pressure which represents the abutment pressure changes when the FBG wavelength shifts1 pm. The distribution pattern of abutment pressure in surrounding rocks is analyzed quantitatively,the abutment pressure and its affected area（ K,L1,L2） are obtained. This study also proposes a mechanic model of abutment pressure distribution,which could be used to quantitatively describe the abutment pressure distribution pattern of mining surrounding rocks.