基于高斯滤波法剪切作用下节理表面形貌演化

Evolution of joint morphology subjected to shear loads based on Gaussian filtering method

选取2类岩石节理试样进行3种法向应力条件下的剪切试验,采用高精度三维激光形貌仪Talysurf CLI 2000获取节理表面三维形貌图,并基于高斯滤波法,将原始节理表面分离为波纹度表面与粗糙度表面,通过计算节理表面粗糙度系数比(S)与表面磨损度(Ds),研究剪切作用下节理表面形貌变化规律。结果表明:起伏体的破坏使得波纹度表面和粗糙度表面的整体粗糙程度均出现明显下降;波纹度表面磨损度随着法向应力的增大而增大,而粗糙度表面磨损度在首次剪切后最大,且大于波纹度表面磨损度;法向应力较低时原始节理表面形貌变化主要取决于粗糙度表面,法向应力较高时节理表面形貌变化则由波纹度表面控制。

Two kinds of rock joint samples underwent a monotonic shear test under three different normal stresses. Three-dimensional laser topography instrument Talysurf CLI 2000 was used to acquire 3D joint surface morphology. Based on Gaussian filtering method, the original joint surfaces were divided into waviness surface and roughness surface, which can be analyzed separately. Then, the morphological evolution of joint surface subjected to shear loads was investigated by analyzing joint specific roughness coefficient （S） and joint surface degradation degree （Ds） quantitatively. The experimental results show that the entire roughness of waviness surface and roughness surface has a clear decline due to the damage of asperities during the shearing process. The degradation degree for waviness surface increases gradually with the increase of normal stress, while the maximum degradation degree for roughness surface appeares after the first shear test and it is greater than the degradation degree for waviness surface. The morphological evolution of original joint surface is mainly dominated by roughness surface and waviness surface, respectively, under low and high normal stresses.