A New Characterization Method for Rock Joint Roughness Considering the Mechanical Contribution of Each Asperity Order

The morphology of the joint surface is multi-scale, and it can be divided into first-order asperity (waviness) second-order (unevenness). At present, roughness characterization formula considers only contribution waviness unevenness components does not fully consider their mechanical contribution. same time, relationship between still unclear. Thus, considering needs to further studied. In this study, standard coefficient (JRC) profiles were first decomposed unevenness. Then, three types specimens with different orders (flat, JRC profile, profile containing waviness) prepared by 3D engraving technique. Finally, direct shear tests carried out on 39 sets red sandstone under normal stresses. contributions studied, was analyzed, established. results showed that following: (1) method combining ensemble empirical mode decomposition (EEMD) critical level could used separate from surface; (2) decreased increase in stress; (3) ratio statistical parameter describe power function; (4) This study will enhance accurate evaluation strength specimen.