Effects of high temperature and thermal cycles on fracture surface's roughness of granite:An insight on 3D morphology  

作　　者：Qixiong Gu Zhen Huang Kui Zhao Wen Zhong Li Liu Xiaozhao Li Yun Wu Ma Dan 

机构地区：[1]Key Laboratory of Mining Engineering of Jiangxi Province,Jiangxi University of Science and Technology,Ganzhou,341000,China [2]School of Resources and Environment Engineering,Jiangxi University of Science and Technology,Ganzhou,341000,China [3]State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,221116,China [4]School of Resources and Earth Science,China University of Mining and Technology,Xuzhou,221116,China [5]School of Mines,China University of Mining and Technology,Xuzhou,221116,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2025年第2期810-826,共17页岩石力学与岩土工程学报(英文)

基　　金：funding support from the National Natural Science Foundation of China(Grant No.52274082);the Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology(Grant No.JXUSTQJBJ2020003);the Innovation Fund Designated for Graduate Students of Jiangxi Province(Grant No.YC2023-B215).

摘　　要：The roughness of the fracture surface directly affects the strength,deformation,and permeability of the surrounding rock in deep underground engineering.Understanding the effect of high temperature and thermal cycle on the fracture surface roughness plays an important role in estimating the damage degree and stability of deep rock mass.In this paper,the variations of fracture surface roughness of granite after different heating and thermal cycles were investigated using the joint roughness coefficient method(JRC),three-dimensional(3D)roughness parameters,and fractal dimension(D),and the mechanism of damage and deterioration of granite were revealed.The experimental results show an increase in the roughness of the granite fracture surface as temperature and cycle number were incremented.The variations of JRC,height parameter,inclination parameter and area parameter with the temperature conformed to the Boltzmann's functional distribution,while the D decreased linearly as the temperature increased.Besides,the anisotropy index(Ip)of the granite fracture surface increased as the temperature increased,and the larger parameter values of roughness characterization at different temperatures were attained mainly in directions of 20°–40°,60°–100°and 140°–160°.The fracture aperture of granite after fracture followed the Gauss distribution and the average aperture increased with increasing temperature,which increased from 0.665 mm at 25℃to 1.058 mm at 800℃.High temperature caused an uneven thermal expansion,water evaporation,and oxidation of minerals within the granite,which promoted the growth and expansion of microfractures,and reduced interparticle bonding strength.In particular,the damage was exacerbated by the expansion and cracking of the quartz phase transition after T>500℃.Thermal cycles contributed to the accumulation of this damage and further weakened the interparticle bonding forces,resulting in a significant increase in the roughness,anisotropy,and aperture of the fracture surface after five cy

关 键 词：GRANITE Thermal cycles High temperature Fracture surface roughness ANISOTROPIC Thermal damage 

分 类 号：TU45[建筑科学—岩土工程]