考虑细观接触的堆石料本构关系研究

Research on the Constitutive Relation of Rockfill Material Based on Micro-contact Consideration

考虑细观接触的堆石料解析模型不仅可以很好地反映堆石料的应力-应变关系,而且可以揭示土体变形和强度发展的细观机理.通过设置特征粒径并采用随围压增加而减小的峰值内摩擦角,将颗粒材料的本构模型应用于堆石料的三轴试验结果模拟中,并采用粒子群优化算法搜寻细观本构模型参数,与试验应力-应变-体变关系比较可以看出,拟合效果很好.表明文中提出的从细观本构出发,构筑堆石料应力-应变关系的方法切实可行.

The analytic model of rockfill material based on micro-contact consideration can well reflect the relations between the stress and the strain of rockfill material,and can reveal the micro-mechanism of soil deformation and strength development. After setting the characteristic particle sizes and adopting the peak internal friction angle which is decreasing with the confining pressure increasing,the constitutive model of the material of particles was applied to the simulation of the results of the conventional triaxial test for rockfill material,and Particle Swarm Optimization algorithm was utilized to search for the micro-constitutive parameters. By comparing the relation among the stress and strain and volumetric strain in the experiment,the fitting results is excellent,which shows that the method of constructing the relation between the strain and stress of rockfill material is feasible from the microstructure.