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The aim of this paper is to investigate the damage cracking characteristics of rock and soil aggregate(RSA)by X-ray computed tomography(CT)under uniaxial compressive loading.The mean CT value for the region of interest(ROI)is used to analyze the cracking characteristics.Also,the mathematical morphology method based on the image threshold segmentation is used to obtain characteristic parameters of cracks to describe the cracking evolution of RSA.Results show that the elastic mismatch between rock blocks and soil matrix is the primary reason for RSA cracking.The mean CT value for the RSA specimen,rock block inclusions,and their adjacent soil regions decreases with the increasing stress level.However,it is more sensitive for block inclusions than soil regions.Using the image segmentation method,length,area and mean width of cracks obey to power function distribution.Crack statistical characteristics are closely related to the rock block’s distribution and morphology.These results may be useful to reveal the mesoscopic cracking mechanism,establish meso-damage evolution equation,and constitutive relation for RSA.
The aim of this paper is to investigate the damage cracking characteristics of rock and soil aggregate (RSA) by X-ray computed tomography (CT) under uniaxial compressive loading. The mean CT value for the region of interest (ROI) is used to analyze the cracking characteristics. Also, the mathematical morphology method based on the image threshold segmentation is used to obtain characteristic parameters of cracks to describe the cracking evolution of RSA. Results show that the elastic mismatch between rock blocks and soil matrix is the primary reason for RSA cracking.The mean CT value for the RSA specimen, rock block inclusions, and their adjacent soil regions decreases with increasing increasing stress level. Now, it is more sensitive for block inclusions than soil regions. Using the image segmentation method, length, area and mean width of cracks obey to power function distribution. Crack statistical characteristics are closely related to the rock block’s distribution and morphology. These results may be useful to reveal the mesoscopic cracking mechanism, establish meso-damage evolution equation, and constitutive relation for RSA.