Surface crack evolution patterns in freeze-thaw damage of fissured rock bodies  

作　　者：KANG Zhiqiang WANG Zhilei SHAO Luhang FENG Jiangjiang YAO Xulong 

机构地区：[1]College of Mining Engineering,North China University of Science and Technology,Tangshan 063200,China [2]Green Intelligent Mining Technology Innovation Center of Hebei Province,North China University of Science and Technology,Tangshan 063210,China [3]Luannan Macheng Mining Co.,Ltd.,Shougang Group Co.,Ltd,Luannan County,Tangshan 063500,China

出　　处：《Journal of Mountain Science》2024年第9期3094-3107,共14页山地科学学报（英文）

基　　金：supported by the National Natural Science Foundation of China(Project No.52074123).

摘　　要：To explore the effects of freeze‒thaw cycles on the mechanical properties and crack evolution of fissured sandstone,biaxial compression experiments were carried out on sandstone subjected to freeze‒thaw cycles to characterize the changes in the physical and mechanical properties of fissured sandstone caused by freeze‒thaw cycles.The crack evolution and crack change process on the surface of the fissured sandstone were recorded and analysed in detail via digital image technology(DIC).Numerical simulation was used to reveal the expansion process and damage mode of fine-scale cracks under the action of freeze‒thaw cycles,and the simulation results were compared and analysed with the experimental data to verify the reliability of the numerical model.The results show that the mass loss,porosity,peak stress and elastic modulus all increase with increasing number of freeze‒thaw cycles.With an increase in the number of freeze‒thaw cycles,a substantial change in displacement occurs around the prefabricated cracks,and a stress concentration appears at the crack tip.As new cracks continue to sprout at the tips of the prefabricated cracks until the microcracks gradually penetrate into the main cracks,the displacement cloud becomes obviously discontinuous,and the contours of the displacement field in the crack fracture damage area simply intersect with the prefabricated cracks to form an obvious fracture.The damage patterns of the fractured sandstone after freeze‒thaw cycles clearly differ,forming a symmetrical"L"-shaped damage pattern at zero freeze‒thaw cycles,a symmetrical"V"-shaped damage pattern at 10 freeze‒thaw cycles,and a"V"-shaped damage pattern at 20 freeze‒thaw cycles.After 20 freeze‒thaw cycles,a"V"-shaped destruction pattern and"L"-shaped destruction pattern are formed;after 30 freeze‒thaw cycles,an"N"-shaped destruction pattern is formed.This shows that the failure mode of fractured sandstone gradually becomes more complicated with an increasing number of freeze‒thaw cycles.The effects

关 键 词：Freeze‒thaw cycles Fissured sandstone Particle flow software Rock mechanics Crack extension pattern DIC technique 

分 类 号：TU45[建筑科学—岩土工程]