考虑细观单粒强度的堆石料破碎特性研究

Modeling particle breakage of rockfill materials based on single particle strength

颗粒破碎是影响堆石料力学性质的主要因素之一,但由于测试手段的限制,荷载作用过程中堆石的颗粒破碎难以实时度量,因而影响堆石料力学特性的深入研究。通过单粒强度试验,发现同一粒组的堆石料单粒强度较好地服从Weibull分布,而破碎后颗粒的粒径级配曲线基本服从分形分布。在此基础上,推求了堆石料三轴试验过程中级配的演化过程,给出了颗粒破碎的实时预测方法,与三轴试验结果比较,验证了本文方法的有效性。

The existing researches indicate that the mechanical properties of rockfill materials are significantly affected by the particle crushing. In order to reproduce the fundamental features of particle breakage, the changes of the particle size distribution（PSD） have to be described in mathematical form, i.e., to track the evolution of the PSD. This is difficult for the triaxial test processes due to the measurability limit of particle breakage. The single particle strength of the rockfill is measured and the crushing sample is sieved. The results show that the strengths of particles obey the Weibull statistics, and that the fractal distribution is found for PSD of crushed aggregates. Based on those findings, the changes of PSD can be described during the triaxial test process, the breakage of the triaxial tests is simulated, and the results reveal that the breakage process well agrees with the experimental data.