Three-dimensional reconstruction and growth factor model for rock cracks under uniaxial cyclic loading/unloading by X-ray CT

• Main Authors: Wang, Chunlai, Gao, Ansen, Shi, Feng, Hou, Xiaolin, Ni, Pengpeng, Ba, Deyang
• Other Authors: School of Civil and Environmental Engineering
• Format: Article
• Language: English
• Published: 2019
• Subjects: CT Scanning; DRNTU::Engineering::Civil engineering; Cyclic Loading/Unloading
• Online Access: https://hdl.handle.net/10356/104721; http://hdl.handle.net/10220/48642
• Institution: Nanyang Technological University

The spatial distribution and propagation of cracks are one of the key factors that can influence the initiation of rock failure. In this investigation, the technique of X-ray computed tomography (CT) scanning was used to survey the pattern of rock cracks during cyclic loading/unloading. The distribution and nonlinear development of rock cracks were explored by three-dimensional (3D) reconstruction for use to quantitatively describe their growth. An entropy model for rock mass and a crack growth factor model were established, which could help to reveal the relation between the crack propagation and the macroscopic destruction.The results showed that all disconnected cracks in two-dimensional (2D) images became connected with each other in 3D images. The fractal dimension of rock cracks was increasing first and then decreasing, which was the result of gradual transformation of rock cracks. The growth rate of cracks was decreased with the increase of the quantity of cracks, which was caused by the retardation. When the quantity of cracks grew to a maximal, the growth rate was reduced to zero.