考虑骨架作用的堆石混凝土三维细观建模方法

Three-Dimensional Mesoscopic Modeling Method of Rock-Filled Concrete Considering Skeleton Effect

摘要:

为避免骨料干涉判断的繁琐过程，快速生成不同堆石率的计算模型，基于堆石混凝土的材料组成和结构特点，利用离散元软件PFC3D提出了一种考虑骨架作用的堆石混凝土三维细观模型生成方法.利用建立的几何模型对考虑及不考虑骨架作用的三维细观模型堆石混凝土进行了单轴压缩试验.结果表明：堆石混凝土内部骨料相互接触形成的传力骨架可以有效提高堆石混凝土的整体强度；考虑骨架作用数值模拟得到的堆石混凝土应力-应变曲线、破坏形态与试验结果更为吻合；该模型能较好地反映骨架作用对堆石混凝土力学特性的影响，为深入研究堆石混凝土损伤演化规律和破坏机理提供了细观力学角度的模型基础.

Abstract:

To avoid the cumbersome process of aggregate interference judgment and rapidly generate calculation models with different rock-filled rates， a method for generating a three-dimensional mesoscopic model of rock-filled concrete considering the skeletal effect was proposed using discrete element software PFC3D， based on the material composition and structural characteristics of rock-filled concrete. Uniaxial compression tests on rock-filled concrete mesoscopic models， both considering and neglecting the skeleton effect， were conducted using the established geometric models. The results indicate that the force transfer skeleton formed by the mutual contact of aggregates inside rock-filled concrete can effectively enhance the overall strength of the material. The stress-strain curves and failure modes of rock-filled concrete obtained from numerical simulations considering the skeletal effect are more consistent with experimental results. This model can effectively reflect the influence of the skeletal effect on the mechanical properties of rock-filled concrete， providing a meso-mechanical model foundation for in-depth studies on the damage evolution laws and failure mechanisms of rock-filled concrete.