应力作用下粒状土颗粒破碎全过程的级配演化规律及其模型预测研究

项目名称： 应力作用下粒状土颗粒破碎全过程的级配演化规律及其模型预测研究

项目编号： No.41272334

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 张季如

作者单位： 武汉理工大学

项目金额： 85万元

中文摘要： 应力作用下颗粒破碎对粒状土的力学性能有很大影响，并主要通过颗粒破碎量反映。由于颗粒破碎直接导致土的级配发生变化，研究颗粒破碎全过程的级配状况及演化规律，对颗粒破碎的力学行为和定量化研究起到重要的贡献。但受技术条件限制，现有实验仅能促成有限程度的颗粒破碎，不足以判断破碎是否终止。本项目以钙质砂和石英砂为研究对象，进行高压下的侧限和三轴压缩试验，研究颗粒破碎过程中的应力应变状态、颗粒级配及其演化规律；基于粒状土颗粒的连续破碎符合分形规律，构建表征粒径分布的分形模型，并通过与试验数据的拟合分析实现优化；利用模型模拟并预测颗粒破碎全过程的级配状况及演化规律，探索破碎终止状态的理论判据，揭示破碎终止时的极限粒径分布和影响因素，研究颗粒破碎对粒状土应力应变状态的影响机制。项目研究将从理论上帮助认识颗粒破碎全过程的粒径分布规律，并进一步完善破碎量化指标的应用，从而促进粒状土颗粒破碎相关理论的研究与发展。

中文关键词： 粒状土；颗粒破碎；粒径分布；演化规律；模型预测

英文摘要： Particle breakage under stresses has a great influence on the mechanical properties of granular soil and is mainly reflected by the amount of breakage. The growth of breakage leads directly to a change grading and describes the evolution of particle-size distribution which plays an important role on the analysis of mechanical response and breakage index. However, only a limited degree of particle breakage can be observed in existing tests due to a limitation of experimental techniques. The stresses or strains that are achievable in existing tests are insufficient to see whether the particle breakage has completely ceased or whether the granular soil will eventually reach a stable grading. This project is aimed towards exploring the evolution of particle-size distribution in the whole process of particle breakage, so identifying whether or not a stable grading can be reached. A series of confined and triaxial compression tests on two sands, one with a carbonate and one a quartz mineralogy, are conducted to investigate the development of particle breakage and the evolution of particle-size distribution and stress-strain relationship with compressive and shear stress. Based on the idea that any initial distribution of particles tends towards a self-similar distribution and particle-size distribution tends to be fra

英文关键词： granular soil；particle breakage；particle-size distribution；evolution；model prediction