基于颗粒破碎特性的堆石材料级配演化模型

颗粒破碎会改变土体级配,进而影响其应力应变等力学行为。针对现有技术手段难以实时确定加载过程中颗粒破碎与级配变化的现状,依据天然岩石颗粒的破碎特性,建立了一个基于颗粒强度的级配演化模型。模型中应力参数采用增量加载法,可预测加载过程中的级配演化。由单粒强度试验确定颗粒破碎特性和模型参数,试验结果表明颗粒强度服从Weibull分布。筛分颗粒破碎后的碎片发现,粒径累计分布可用正态曲线拟合,且不同粒组的粒径累计分布相似。最后,模型计算结果与三轴试验数据的对比分析表明,模型可以较好地预测试样在加载过程中的级配变化。

Gradation evolution model based on particle breakage characteristics for rockfill materials

Particle crushing will change the density and gradation curves of geotechnical materials, and then influence their stress-strain behavior. The proposed gradation evolution model, based on the particle breakage characteristics of natural rocks, is to obtain the information of particle breakage and gradation which is difficult to be dealt with by normal technical means during loading process. The stress parameter of the model adopts the incremental loading method, so the model can predict the evolution of gradation during experimental process. The particle breakage characteristics and model parameters are determined through the crushing tests on a single particle. The experimental data obtained from the tests show that the particle strength obeys the Weibull distribution. In addition, the grain-size distributions after crushing tests are normally distributed, and the distributions of different groups are similar. Finally, the proposed model is proved to be able to predict the gradation variation of rockfill materials correctly through comparative analysis of the calculated results and triaxial test data.