滇西地区九种岩石的P波Q值

THE Q-VALUE OF P WAVES OF 9 DIFFERENT TYPES OF ROCKS FROM WESTERN YUNNAN PROVINCE, CHINA

本文叙述了以波传播和谱振幅比法测得的滇西地区九种岩石在不同应力状态下(σ_1=σ_2=σ_3=σ)的衰减系数,P波速度及Q值。在σ≤90 MPa时,随压力增加,衰减系数减小,P波速度及Q值增大;在σ≥120 MPa以后,衰减系数、P波速度及Q值变化甚小。其中团山砂岩及砖窑村片麻岩Q值较低。

Using the propagation and spectral amplitude ratio approaches, measurements were made to obtain the attenuation coefficients, P wave velocities and Q-values under respective stress conditions (σ1=σ2=σ3=σ) for 9 different types of rocks collected in western Yunnan Province, China. At σ≤90 MPa, the attenuation coefficient decreases whereas the P wave velocity and Q-value increase when the pressure increases. At σ≥120 MPa and afterwards, the attenuation coefficient, P wave velocity and Q-value do not manifest significant changes. Tuanshan sandstone and Zhuanyao Village gneiss show relatively-low Q-values.