基于单粒压缩试验的堆石料破碎特性研究

Study on broken characteristics of rockfill materials based on single particle compression test

堆石料的颗粒破碎是影响其强度及变形的主要因素,但堆石料在受力过程中的颗粒破碎规律仍不明确,缺乏准确判断堆石料颗粒破碎的标准。单粒压缩试验是研究堆石料破碎特性的重要手段,通过可视化单粒压缩试验对920组不同粒径玄武岩堆石料颗粒的破碎过程进行了研究。试验结果表明:玄武岩堆石料单粒压缩破碎的过程大致可分为4个阶段,破碎模式可分为3种类型,破碎程度随粒径的减小而增大;同一粒组的堆石料单粒强度较好地服从Weibull模型,随着试验样本量的增加,峰值应力分布逐步趋向正态分布;破碎颗粒的级配分布与破碎模式相关,多应力峰值破碎颗粒的碎后粒径级配曲线服从分形分布。

Particle breakage is a key factor that influences rock-fill strength and deformation.However,particle breakage laws of rock-fill material are still unclear and the breakage standard of the rock-fill particles is also absent.Single-particle compression test is a key method to study the breakage characteristics of rock-fill particles.In this test,920 groups of visual-single-particle compression experiments were performed,by which the failure process of different size particles were investigated.It is noted that the destruction process of particles can be divided into four stages and the failure modes can be divided into three types.Moreover,the damage of broken particle increased with the decrease of particle size.The single-particle strength parameters of the same size could be accurately simulated by the Weibull model.As the samples increase,the distribution of peak strength gradually tends to be the normal distribution.Furthermore,gradation distribution of the broken particles is related to the failure mode.Particle gradation of the broken particles,which reveals several peak strengths,conforms to fractal distribution.