Evolution of Shear Surface Morphology of Jointed Rock Masses Based on Gaussian Filtering Method under Freeze-Thaw Cycles

Materials

Chunshun Zhang¹  Guangli Wang²  Zhigang Lu²  Yaoping Zhang²  Daxing Lei²  Hang Lin³  Yifan Chen³ 

[1] Department of Civil Engineering, Monash University, Clayton, VIC 3800, Australia;School of Resources and Architectural Engineering, Gannan University of Science and Technology, Ganzhou 341000, China;School of Resources and Safety Engineering, Central South University, Changsha 410083, China;

关键词: freeze-thaw cycles;    direct shear experiment;    Gaussian filtering;    shear surface morphology;    large-scale waviness surface;    small-scale unevenness surface;   

DOI  :  10.3390/ma15124228

来源: DOAJ

【 摘 要 】

This study aims to quantify the shear surface morphology of jointed rock and its evolution under shearing, cyclic freezing, and thawing using the Gaussian filtering method. Gaussian filtering method enables the construction of the (large-scale) waviness surface and the (small-scale) unevenness surface of a digitized surface (created by laser scanning). Both waviness and unevenness surfaces are then quantified by roughness coefficient ratio (S) and degradation degrees of the waviness surface (D_w) and unevenness surface (D_r). These (microscopic) morphological parameters (S, D_w and D_r) are subsequently used to explain the development of the (macroscopic) shear strength of the jointed rocks on direct shear tests. The results indicate that compared with fresh jointed rocks, the freezing and thawing causes the potential shear surface asperities to be easier to damage and fail under shear load. Such damage is well represented by the significant decrease in D_w and D_r. On the other hand, with the increase of the freeze-thaw cycle (N), D_w increases while D_r reaches the maximum at an early stage of the cycle, where D_r > D_w. This difference reveals the underlying shear mechanism microscopically; that is, in the initial stage, the shear surface morphology is mainly dominated by the unevenness surface D_r, and then it is controlled by the waviness surface D_w during the freeze-thaw cycle.

【 授权许可】

Unknown