a College of Mechanics and Materials, Hohai University, Nanjing, 210098, China
b College of Energy and Electrical Engineering, Hohai University, Nanjing, 210098, China
2023, 15(6): 1565-1579. doi:10.1016/j.jrmge.2022.09.017
Received: 2022-04-26 / Revised: 2022-07-09 / Accepted: 2022-09-15 / Available online: 2023-02-25
2023, 15(6): 1565-1579.
doi:10.1016/j.jrmge.2022.09.017
Received: 2022-04-26
Revised: 2022-07-09
Accepted: 2022-09-15
Available online: 2023-02-25
Calcareous sand is typically known as a problematic marine sediment because of its diverse morphology and complex inner pore structure. However, the coupling effects of morphology and inner pores on the mechanical properties of calcareous sand particles have rarely been investigated and understood. In this study, apparent contours and internal pore distributions of calcareous sand particles were obtained by three-dimensional (3D) scanning imaging and X-ray micro-computed tomography (X-μCT), respectively. It was revealed that calcareous sand particles with different outer morphologies have different porosities and inner pore distributions because of their original sources and particle transport processes. In addition, a total of 120 photo-related compression tests and 492 3D discrete element simulations of four specific shaped particles, i.e. bulky, angular, dendritic and flaky, with variations in the inner pore distribution were conducted. The macroscopic particle strength and Weibull modulus obtained from the physical tests are not positively correlated with the porosity or regularity in shape, indicating the existence of coupling effect of particle shape and pore distribution. The shape effect on the particle strength first increases with the porosity and then decreases. The particle crushing of relatively regular particles is governed by the porosity, but that of extremely irregular particles is governed by the particle shape. The particle strength increases with the uniformity of the pore distribution. Particle fragmentation is mainly dependant on tensile bond strength, and the degree of tensile failure is considerably impacted by the particle shape but limited by the pore distribution.
Keywords: Calcareous sand, Coupling effects, Outer shape, Internal pore distribution, Particle strength, Failure mode
Yaru Lv
Yaru Lv is Professor at Hohai University, China. She obtained her MSc and PhD degrees in Geotechnical Engineering from Hohai University, China. Her research interests include the dynamic behavior of soil at high strain rates, the strain rate effects and simulation method for large deformation of soil, and soil–structure interactions. She has vast practical experiences in laboratory and field tests, self-developed numerical method, and constitutive model. She has been participating in three National Natural Science Foundations of China, Hong Kong Scholars Program and the Young Elite Scientist Sponsorship.