考虑颗粒形状和破碎的胶结钙质砂力学行为离散元模拟研究

In recent years, carbonate sand has been widely used as a type of construction materials in the South China Sea Project. In this paper, the macro- and micro-scale mechanical behavior of cemented carbonate sand under biaxial compression was investigated using a discrete element model incorporating the effects of realistic particle shape and particle breakage. The stress-strain behavior and the evolution of particle and cement bond breakage, displacement field and crack distribution were studied. The effects of particle shape, particle size distribution, particle strength and cement strength on the mechanical behavior of cemented carbonate sand were analyzed. It was found that a larger size distribution of carbonate sand particles leads to a higher peak strength of the cemented carbonate sand. The cemented carbonated sand specimen with realistic particle shape exhibited a higher peak strength and a higher particle breakage degree than that with a round particle shape. The cemented carbonate sand with higher particle sand strength usually had better mechanical properties. However, the mechanical behavior of cemented carbonate sand could not be significantly improved by merely improving the cement strength. This study could provide a theoretical basis for the reinforcement of carbonate sands in engineering applications.