筑坝粗粒料力学特性的缩尺效应研究  

Research on scale effect of coarse-grained materials

作　　者：王永明[1,2] 朱晟[3] 任金明[1] 彭鹏[1] 徐学勇[1,2] 

机构地区：[1]中国水电顾问集团华东勘测设计研究院,杭州310014 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071 [3]河海大学水文水资源与水利水电工程科学国家重点实验室,南京210098

出　　处：《岩土力学》2013年第6期1799-1806,1823,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.41101519);中国水电顾问集团华东勘测设计研究院院立项课题(No.KY2010-02-14)

摘　　要：针对筑坝粗粒材料缩尺效应问题,统计分析三板溪、水布垭等大坝填筑料的级配特征,认为以Talbot曲线为原级配可作为高土石坝填筑料的"平均级配",并将此原级配按现今粗粒料试验制样时最为常用的"混合法"进行缩尺,配制了最大粒径dmax为20～180 mm的试样。利用PFC2D软件,对各缩尺级配进行了多组、多种数值试验,揭示了各缩尺级配试样干密度极值、初始弹性模量及体积模量等关键物理量与各级配最大粒径的关系。结果表明:缩尺关系与密实度控制标准相关,在同一相对密度条件下各缩尺比试样力学参量为其最大粒径的单调函数,经推求可得原级配具备室内试验级配1.5～1.6倍的抗变形能力;而在同一干密度条件下,力学参量与各最大粒径呈先减小再增加的非单调关系。最后基于细观力学理论对造成缩尺效应的机制进行了解译。利用PFC2D数值试验从一定程度上拓展了仅靠实际三轴试验来研究粗粒料缩尺效应的粒径和思路。In order to investigate the scale effect of coarse-grained materials, the gradations of Sanbanxi and Shuibuya dam rockfills are statistically analyzed. The Talbot curve can be used as the original ＂average gradation＂ for high rockfill dam after analysis. This original gradation curve is scaled utilizing the mixing method which is widely used in projects to compound samples whose maximum particle size distributed from 20 to 180 mm. The relationships between characteristic parameters such as dry density, initial elastic modulus and bulk modulus and the maximum particle size of each group samples are revealed after many sets of numerical experiments which conducted by PFC2D. The results show that the scale effect is related to density control standard. The mechanical parameters are monotone function about the maximum particle size, and the original gradation has 1.5 to 1.6 times anti-distortion capacity of scaled laboratory gradation under the same relative density condition. On the other hand, mechanical parameters are non-monotone function under the same dry density condition. Finally, the mechanical mechanism of scale effect is interpreted with mesomechanics. The particle size and thought are expanded on the basis ofPFC2D numerical test.

关 键 词：粗粒料 缩尺效应 Talbot曲线 细观力学 

分 类 号：TV641[水利工程—水利水电工程]