Study on the shear behavior at the interface between surrounding rock and backfill material under varying roughness conditions
SUN Xuqiang
TANG Bin
LIU Xiaohu
ZHAO Neng
WANG Pengrui
LIU Bohan
SHI Wangdong
Abstract：The roughness of rock joints,as a critical parameter governing the mechanical behavior of rock mass interfaces,necessitates in-depth investigation into its correlation with shear strength for significant engineering implications.In this study,molds were initially fabricated using 3D printing technology to cast interface contact specimens with varying roughness levels(Joint Roughness Coeffi-cient JRC=3,8,13,18,21).Oblique shear tests at 45° inclination were conducted on these specimens through a WAW-2000 microcomputer-controlled electro-hydraulic servo universal testing machine,ac-quiring load-displacement curves for interfaces with distinct roughness characteristics.The influence patterns of roughness on shear behavior were systematically analyzed,while Digital Image Correlation technique was concurrently employed for dynamic monitoring of displacement and strain fields.The research findings demonstrate that joint roughness exerts a significant influence on the shear strength of interface contact specimens.The JRC value substantially affects the failure morphology,with shear strength exhibiting a positive correlation with increasing JRC values.Enhanced roughness induces a transition in shear failure mode from the sliding of filling materials to structural failure,revealing that surface morphology plays a decisive role in controlling the mechanical behavior of rock mass interfaces.This investigation provides quantitative evidence for understanding the roughness-dependent shear mecha-nisms in rock discontinuity systems.
Keywords：interface roughnessjoint roughness coefficientslant shear testdigital image correlation(DIC)interfacial bonding performance
Publication Date：2025-12-31
Online Publishing Date：2025-11-25(First online date of this platform, not the publication date of the document)
Pages：7( 61-66,20 )