黏弹介质槽波超前探测数值模拟与波场分析  

Numerical simulations and wavefield analysis of in-seam wave advance detection in viscoelastic media

作　　者：何帝秀 姬广忠 焦文杰 张亚伟 于坤 HE Dixiu;JI Guangzhong;JIAO Wenjie;ZHANG Yawei;YU Kun(School of Earth and Environment,Anhui University of Science&Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学地球与环境学院,安徽淮南232001

出　　处：《煤田地质与勘探》2023年第10期144-155,共12页Coal Geology & Exploration

基　　金：国家自然科学基金项目(42074148);安徽省自然科学基金项目(2208085Y14)。

摘　　要：目前常用槽波超前探测掘进工作面前方隐伏断层,而实际煤层具有黏弹性,对槽波有吸收衰减作用。为研究黏弹煤层介质中槽波超前探测的波场特征和传播规律,基于Kelvin-Voigt一阶速度−应力方程,建立了三维含断层煤系地质模型,进行了三维有限差分数值模拟。结果表明:黏弹介质中反射槽波能量衰减大,其传播与衰减特征比完全弹性介质更符合实际煤层反射槽波传播特征。煤层Q值越大槽波超前探测效果越好,煤层Q值过小时,槽波超前探测效果差,可利用x分量的反射横波与z分量的P-S波超前探测。断层落差小于煤厚时,y和z分量的槽波超前探测效果都较好;落差大于煤厚时,可利用y分量进行槽波超前探测。断层夹角大于60°时,可利用y和z分量进行槽波超前探测;夹角小于60°时,可利用x和y分量进行槽波超前探测。研究结果可为煤矿槽波超前探测提供理论支持。In-seam waves are commonly applied to the advance detection of hidden faults in front of mining faces.However,coal seams,which have viscoelasticity actually,imposing absorptive and attenuation effects on in-seam waves.To investigate the wave field characteristics and propagation patterns of in-seam waves in viscoelastic coal seam media,this study built a three-dimensional geological model of coal measures with faults based on Kelvin-Voigt’s first-order velocity-stress equation.Using this equation,three-dimensional finite-difference numerical simulation was carried out.The results indicate that(1)for reflected in-seam waves in viscoelastic media,which exhibit high energy attenuation,their propagation and attenuation characteristics are more consistent with the actual situation of coal seams than those of reflected in-seam waves in completely elastic media.(2)High Q values of coal seams correspond to better advance detection effects of in-seam waves.By contrast,too low Q values are associated with poor advance detection effects.In this case,the x component of reflected shear waves and the z component of the P-S waves can be used for advance detection.(3)When the fault throw is less than the coal thickness,the y and z components of in-seam waves can yield great advance detection effects.When the fault throw is greater than the coal thickness and above,the y component of in-seam waves can be employed for advance detection.(4)When the angle between a fault plane and the tunnel is greater than 60°,the y and z components of in-seam waves can be employed for advance detection.When the angle is less than 60°,the x and y components of in-seam waves can be used for advance detection.The results of this study could provide theoretical support for the in-seam wave advance detection of coal mines.

关 键 词：槽波 煤层 黏弹性 数值模拟 超前探测 波场特征 

分 类 号：P631[天文地球—地质矿产勘探]