摘要
针对已有研究成果忽视密实度缩尺效应对粗粒筑坝料力学性质影响的问题,根据双江口300m级土石坝堆石料的原平均设计级配曲线,采用4种不同缩尺方法得到室内干密度极值试验成果,利用粗粒筑坝材料的级配设计母线——Talbot曲线,引入分形几何理论,选取对级配性质较为敏感的Talbot公式的指数n以及反映颗粒形状与粗糙度的因子作为分形指标,解译粗粒料密实度出现缩尺效应的内在原因,为粗粒料级配构成对密实度影响的量化评价提供依据,克服以往只能利用不均匀系数和曲率系数进行模糊评价的缺点。利用PFC2D软件,结合混合法各缩尺比级配进行干密度极值数值试验,研究缩尺效应对粗粒料的相对密度、孔隙率的影响规律,并分析引起其差异的细观机制。
The scale effect of density on the mechanical properties of coarse-grained dam materials is ignored in previous studies. On this basis,four scale methods are used to obtain the maximum dry density in laboratory according to the original average design gradation curve of rockfill in Shuangjiangkou earth-rockfill dam. Based on the design generatrix of the coarse-grained dam materials gradation-Talbot curve and fractal geometry theory,the mechanism of scale effect of density for coarse-grained dam materials is interpreted,which selects the Talbot formula index and the factor reflecting the particle shape and roughness as the fractal indices. The basis of quantitatively evaluating the effect of gradation on density is provided;and the shortcomings of fuzzy evaluation only using the non-uniformity coefficient and curvature coefficient is overcome. Combined the mixed scale method,the numerical tests on the maximum dry density is carried out by using the particle flow code in two dimensions（PFC2D）;the law of scale effect on the relative density and porosity of coarse-grained materials is studied;and the microscopic mechanism causing the difference is analyzed.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2011年第2期348-357,共10页
Chinese Journal of Rock Mechanics and Engineering
基金
"十一五"国家科技支撑计划项目(2008BAB29B02)
关键词
水利工程
土石坝
粗粒料
密实度
缩尺效应
分形几何
hydraulic engineering
earth-rockfill dam
coarse-grained materials
density
scale effect
fractal geometry
作者简介
朱晟（1965-），男，博士，1988年毕业于河海大学水工专业，现任教授、博士生导师，主要从事土石坝等水工岩土与环境岩土方面的教学与研究工作。E—mail：szhu@hhu．edu．cn
