摘要
煤层是典型的黏弹各向异性介质,将黏弹性和各向异性两种性质结合起来的槽波研究较少。以弱各向异性煤层为研究对象,应用Thomsen等效介质理论,采用Kelvin-Voigt黏弹性模型,研究了黏弹TI(Transverse Isotropy)介质3层水平层状模型Love槽波频散与衰减特征;推导了3层水平介质的Love槽波频散方程解,可以计算品质因子随频率变化的情况;分析了各向异性参数γ、煤层横波品质因子Q_(s)值变化及煤层Q_(s)随频率变化对Love槽波频散、品质因子和衰减曲线的影响;模拟了煤层Q_(s)=10和Q_(s)=20时三维槽波波场传播过程。结果表明:TI介质和各向同性介质的槽波品质因子和衰减系数基阶曲线差别小,各向异性参数γ对Love槽波品质因子和衰减系数影响较小;煤层Q_(s)对Love槽波频散曲线影响很小,主要影响槽波品质因子和衰减系数曲线,煤层Q_(s)=10时槽波衰减系数值比Q_(s)=20和30时大很多;目前煤层Q_(s)在0~1000 Hz内是否随频率变化尚无定论,假设煤层Q_(s)随频率线性减小,各阶槽波品质因子曲线低频部分差异很小,高频部分差异变大,当Q_(s)减小到10时,槽波衰减系数随频率增长很快;对于三维槽波波场,煤层Q_(s)=20时透射Love槽波和基阶Rayleigh槽波能量较强,而Q_(s)=10时这些波衰减很快,对面巷道接收不到,说明实际工程中接收不到这些波的原因很可能是由于煤层Q_(s)很小;针对实际工作面探测中接收不到Love槽波和基阶Rayleigh槽波的情况,可以利用速度较高、衰减相对较小的高阶Rayleigh槽波探测。
The coal seam is a typical viscoelastic anisotropic medium.At present,there is little research on channel waves that combine viscoelasticity and anisotropy.By taking weakly anisotropic coal seams as the research object,applying the Thomsen equivalent medium theory,and adopting the Kelvin-Voigt viscoelastic model,the frequency dispersion and attenuation characteristics of the Love channel waves in the horizontal three-layer model of viscoelastic TI(Transverse Isotropy)medium is studied.The solution of dispersion equation of the Love channel waves for the horizontal three-layer model is derived,which can calculate the case that the quality factor parameter changes with frequency.The influence of the anisotropic parametersγ,the change of coal seam Q_(s)(shear wave quality factor)and the change of Q_(s)with frequency on the dispersion and attenuation characteristics of Love channel waves is analyzed.The propagation process of 3D(three dimensional)channel wave field with coal seam Q_(s)of 10 and 20 is simulated.The following conclusions can be obtained.The difference between the quality factor and attenuation coefficient curves of the fundamental-mode Love channel waves of TI and isotropic medium is small.The anisotropic parameterγhas little effect on the quality factor and attenuation coefficient of the Love channel waves.The Q_(s)of the coal seam has little influence on the velocity dispersion curves of the Love channel waves,and it mainly affects the quality factor and attenuation coefficient curves of the Love channel waves.When the Q_(s)of the coal seam is 10,the value of attenuation coefficient of the love channel waves is much larger than that the Q_(s)is 20 and 30.Whether the Q_(s)of the coal seam changes with frequency within the range of 0-1000 Hz is not yet definitive at present.Assuming that the Q_(s)of coal seam decreases linearly with frequency,the difference of the low-frequency part of the quality factor curves is small,the difference in the low-frequency part of the quality factor curves of differen
作者
姬广忠
吴荣新
张平松
郭立全
胡泽安
焦文杰
JI Guangzhong;WU Rongxin;ZHANG Pingsong;GUO Liquan;HU Zean;JIAO Wenjie(State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan 232001,China;Key Laboratory of Mine Geological Disaster Prevention and Environment Protection of Anhui Higher Education Institutes,Anhui University of Science and Technology,Huainan 232001,China;School of Earth and Environment,Anhui University of Science and Technology,Huainan 232001,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2021年第2期566-577,共12页
Journal of China Coal Society
基金
国家自然科学基金面上资助项目(42074148)
国家重点研发计划资助项目(2018YFC0807804-3)
安徽省重点研发计划资助项目(1804a0802213)。
关键词
煤层
Love槽波
黏弹
TI介质
频散
衰减
coal seam
Love channel wave
viscoelasticity
TI medium
dispersion
attenuation
