冲击倾向煤岩纵波波速与应力关系试验研究

Experimental Study on the Correlation Between Stress and P-Wave Velocity for Burst Tendency Coal-Rock Samples

为了弄清煤矿中冲击矿压现象的发生机理,在实验室单轴条件下对冲击倾向性煤岩样的应力与纵波波速耦合关系进行了研究,建立了两者关系的试验模型,并对模型参数进行了分析。研究结果表明:1)岩样纵波波速对应力的敏感程度要高于煤样,即随应力增加,纵波波速变化更快;2)冲击倾向煤岩试样在弹性阶段纵波波速变化梯度大,塑性阶段波速变化趋于平缓,它表明应力与纵波波速间具有幂函数关系,与实测值的相关系数计算说明,模型具有较高的拟合度,能准确描述应力与波速的变化关系,并服务于现场层析成像冲击危险性计算。

To explore the mechanism of rockburst,we established the experimental model between stress and P-wave velocity for burst tendency coal and rock samples from deep coal mine under the uniaxial loadings,and analyzed the parameters of the derived model.The results show that：1） the P wave velocity in rock sample changes more sensitively than that in coal sample under loadings,which means the P wave velocity in rock sample changes more quicker with the increase of stress;2） the velocity gradient of the sample is usually high at the elastic stage and then begins to level out at the plastic stage under the uniaxial loading,which shows that a power function is exist between the P-wave velocity and stress.The calculated correlation coefficients to measured value show that the experimental model has high fitness,and can be well used to describe the stress distribution and identify the risk level of rockburst in mines.