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Discrete element modelling of the mechanical behavior of cemented carbonate sand considering the effects of particle shape and breakage

DOI：10.7511/jslxCMGM202207

 作者 单位 E-mail 程壮 武汉理工大学 土木工程与建筑学院, 武汉 430070 侯敏 哈尔滨工业大学(威海) 海洋工程学院, 威海 264209 王剑锋 香港城市大学 建筑学与土木工程系, 香港 999077 jefwang@cityu.edu.hk

质砂作为一种建筑材料,近年来广泛应用于我国南海岛礁工程建设中。本文通过建立考虑钙质砂真实颗粒形状和颗粒破碎的胶结钙质砂离散元模型,研究了二维剪切条件下试样的宏微观力学行为,包括应力-应变行为、颗粒破碎、胶结破坏、位移场和裂纹随剪应变的演化规律,讨论了颗粒形状、颗粒粒径范围、颗粒强度和水泥胶结强度对胶结钙质砂力学行为的影响规律。结果表明,钙质砂颗粒粒径区间越宽,胶结钙质砂的强度越高。同一级配条件下,考虑真实颗粒形状的胶结钙质砂试样比圆颗粒试样的强度更高,试样总体颗粒破碎率也更高。钙质砂颗粒的强度越高,胶结钙质砂的性能越好。但是提高水泥的强度对胶结钙质砂力学性能的影响并不显著。本文的研究结果可为实际工程中钙质砂的加固提供理论依据。

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.