自适应连续体/非连续体周期边界单元耦合技术在等效岩体中的应用研究

RESEARCH ON APPLICATION OF COUPLING TECHNIQUE OF ADAPTIVE CONTINUUM/DISCONTINUUM PERIODIC BOUNDARY CELL TO EQUIVALENT ROCK MASS

介绍一种新颖的PFC颗粒流程序计算模型构建方法,即:自适应连续体/非连续体(AC/DC)周期边界单元耦合技术。该方法首先构建压实并达到力学平衡的周期组块,通过复制周期组块镜像快速建立颗粒体模型,因此,可避免模型在生成过程中耗费大量时间达到力学平衡状态的缺陷,从而大幅降低计算时间、节省计算资源。以一等效岩体单轴压缩试验为例,在相同初始计算条件下,比较分析AC/DC技术和常规颗粒体模型构建方法得到的计算结果,两者在单轴抗压强度、应力–应变曲线和变形破坏特征等方面表现出高度相似性,表明在保证计算结果准确性的前提下,AC/DC技术的计算效率远高于常规颗粒体模型构建方法,且这种优势将随着颗粒体规模的增大而越发突出。因此,该技术的应用可为后续研究工程尺度节理岩体力学性质等科学问题奠定坚实基础。

The coupling technique of adaptive continuum/discontinuum（AC/DC） periodic boundary cell, as a new construction method of calculation model in PFC based on particle flow theory, was introduced. In this method, a compacted and balanced pbrick was constructed; and then it was replicated mirrorlikely to construct particles model. Therefore, with decreasing computing time and saving computing resource greatly, it can avoid the defect of consuming great time in the generation of model to reach the mechanical equilibrium state. Taking an uniaxial compression test of equivalent rock mass for example, under the same initial calculation condition, the results produced by AC/DC technique and general method were compared in uniaxial compressive strength, stress-strain curves and failure characteristics, displayed highly similarity. The research results show that the computational efficiency of AC/DC technique is much higher than that of general particles construction method, and the advantage will be particularly prominent with the increment of model size. So its implementation of AC/DC technique can lay a solid foundation for following scientific research of engineering-scale rock mass property.