粗粒料试验缩尺效应的分析研究

Analysis of scale effect of coarse-grained materials

为了对粗粒料缩尺效应有全面的认识,对粗粒料缩尺效应的表现形式进行了系统地阐述,可分为密实度缩尺效应和力学特性缩尺效应。以此为准,整理了前人的研究成果,并总结了缩尺效应的表现规律。密实度缩尺效应规律为:最大粒径越大,则最大或最小干密度越大,且这种规律与缩尺方法无关。此规律可从级配、颗粒形状及压实功3个方面进行解释。力学特性缩尺效应规律为:同一干密度制样标准下,抗剪强度和变形模量均随最大粒径增大而减小,这可从密实度和颗粒强度两个方面进行解释;但同一相对密度制样标准下,力学特性缩尺规律不统一,机制不清晰,需进行进一步地研究。

To understand scale effect of coarse-grained materials,the forms of scale effect are systematically clarified.The scale effect is divided into dense degree scale effect and mechanical properties scale effect.We analyze results of previous studies and summarize the performance of the law.The scale effect of dense degree is that the maximum or minimum dry density increases with the growth of the maximum diameter,which is regardless of scale methods.The law can be explained in terms of gradation,particle shape and compaction energy.With regard to the scale effect of mechanical properties,for the specimens with the same dry density,both shear strength and modulus decrease with the increase of the maximum diameter,which is resulted from compaction degree and particle strength.However,under the criterion of the same relative density,the law of scale effect of mechanical properties is unclear,and thus further studies need to be conducted.