岩石衰减系数与物理力学参数关系分析

Relationship between rock attenuation coefficient and physical and mechanical parameters

纵波在岩石传播过程中,随着传播距离的增加,表现出一定能量衰减特性。本次研究中,通过采用长短岩样对比法测定波幅的衰减系数,分析了衰减系数与多个物理力学参数的数学关系。试验结果表明:衰减系数与岩石的密度、含水率、单轴抗压强度、动静弹性模量、纵波波速、阻尼比具有正相关性,与孔隙率具有负相关性,线性相关系数多为0.6~0.9。衰减系数在不同状态(饱和、天然、干燥)岩石中,表现出不同的衰减特征,一般饱和状态的衰减系数最大,天然状态次之,干燥状态最小。本文对两种衰减系数进行了对比分析,证明了衰减系数是反映岩石本身特性的一种性质;同时用衰减系数反演物理力学参数进行了分析,说明衰减系数可以作为判定工程地质中岩石物理力学性质的一种基本参数。

In the process of P-wave propagation in rock,with the increase of propagation distance,it shows certain energy attenuation characteristics.In this study,the attenuation coefficient of wave amplitude is measured by the comparison method of long and short rock samples,and the mathematical relationship between the attenuation coefficient and multiple physical and mechanical parameters is analyzed.The test results show that the attenuation coefficient has a positive correlation with rock density,water content,uniaxial compressive strength,dynamic and static elastic modulus,longitudinal wave velocity and damping ratio,and a negative correlation with porosity.The linear correlation coefficient is mostly between 0.6-0.9.The attenuation coefficient shows different attenuation characteristics in different states(saturated,natural and dry).Generally,the attenuation coefficient in saturated state is the largest,followed by natural state and dry state.In this paper,two kinds of attenuation coefficients are compared and analyzed,and it is proved that the attenuation coefficient is a property reflecting the characteristics of rock itself.This paper also analyzes the inversion of physical and mechanical parameters by attenuation coefficient,which shows that attenuation coefficient can be used as a basic parameter to determine the physical and mechanical properties of rock in engineering geology.