随机粗糙充填节理对S波传播影响的数值研究

Numerical Study on the Effect of a Random Rough Filled Joint on S-wave Propagation

充填节理对岩体的力学特性有着重要影响,节理面不规则引起的粗糙度使S波在节理岩体中的传播规律变得更加复杂。考虑节理接触面的随机粗糙度与充填材料的塑性变形,通过离散元方法对S波在充填节理岩体中的传播规律进行数值模拟,采用中线截距平均值与起伏均方根量化描述节理的随机粗糙度,分析了不同随机粗糙度下充填厚度与节理剪切强度对透射波形及透射系数的影响。结果表明,与平直节理不同,随机粗糙充填节理对不同入射波波幅下的S波传播规律影响更加明显。同一中线截距平均值下,节理起伏均方根越大,S波透射系数越大;同一节理起伏均方根下,中线截距平均值越小,S波透射系数越大。节理粗糙度对S波衰减规律的影响与充填厚度有着密切的关系。

A filled joint has an important influence on the mechanical properties of rock mass.The roughness caused by the irregularity of the joint surface makes the S-wave propagation in the jointed rock mass more complicated.Considering the random roughness of joint contact surfaces and the plastic deformation of the filled material,numerical study on the S-wave propagation in filled jointed rock mass by the discrete element method is carried out.The average value of midline intercept and the root mean square of fluctuation are used to quantitatively describe the random roughness of joints.The influence of filled thickness and shear strength of joints on transmission waveforms and transmission coefficients under different random roughness is analyzed.The results reveal that,unlike planar joints,the influence of random rough filled joints on the S-wave propagation under different incident wave amplitudes is more obvious.When the average value of midline intercept of a joint is the same,the S-wave transmission coefficient increases with increasing root mean square of fluctuation.When the root mean square of fluctuation is the same,the S-wave transmission coefficient increases with decreasing average values of midline intercept.The effect of the roughness of a joint on the attenuation of S-wave is closely related to the filled thickness.