摘要
粗粒土同一颗粒破碎效应的量化指标存在相互换算关系。根据粒径级配曲线及分形理论,散粒体材料颗粒破碎效应量化指标主要有颗粒破碎量Bg、相对破碎率Br及分形维数D,详细论述三者建立基础及过程,查明其联系与区别。根据不同应力下粗粒土受剪破碎的筛分结果,探讨Br及D随围压变化规律,论证并建立Br与D的数学表达式,揭示了颗粒破碎量化指标的内在逻辑。理论及试验结果分析表明:Bg为数据点间距离代数和,属一维指标;Br及D均基于面积变化量刻画颗粒破碎程度,属二维指标,本质上都是利用增量量化破碎程度。用破碎势量化混合法缩尺效应Br为0.125,用分形理论得到土体缩尺后D减小9.04%。Br随围压增大呈指数变化;D随围压增加呈线性分布,随Br增加呈对数函数变化。
There is an intrinsic relationship between different quantitative indexes of the same particle breakage effect for coarse-grained soil.According to the particle size distribution curve and the fractal theory,the quantitative indexes mainly include the particle breakage B g,the relative breakage rate B r and the fractal dimension D.Subsequently the foundation and process of establishing those three indexes are discussed in detail,and the relationship and differences between them are ascertained.Based on the sieving results of coarse-grained soil under different stress,the variation of B r and D with confining pressure are discussed,and the mathematical expression between B r and D is early proved and established later,which reveals the inherent logic of quantitative index.The theoretical and experimental results show that B g is the algebraic sum of the distance between data points and belongs to one-dimensional index.Further,both B r and D are two-dimensional indicators to describe the degree of particle breakage based on area change,essentially,they use increment to quantify the degree of particle breakage.The scaling effect,which is equal to B r of 0.125,can be quantified by fragmentation potential method,and D decreases by 9.04%after scaling.B r varies exponentially with the increase of confining pressure,while D varies linearly with the increase of confining pressure.D varies logarithmically with the increase of B r.
作者
宋兴海
任永旺
刘子苑
孙晓勇
SONG Xing-hai;REN Yong-wang;LIU Zi-yuan;SUN Xiao-yong(School of Civil Engineering,Hebei University of Water Resources and Electric Engineering,Cangzhou 061001,China;Dayuan Engineering Group Co Ltd,Cangzhou 061001,China)
出处
《土木工程与管理学报》
北大核心
2020年第2期158-162,169,共6页
Journal of Civil Engineering and Management
基金
河北省教育厅自然科学类重点项目(ZD2017055)。
关键词
颗粒破碎
量化指标
相对破碎率
分形维数
particle breakage
quantitative index
relative breakage rate
fractal dimension
作者简介
宋兴海(1982-),男,河北南皮人,硕士,讲师,研究方向为土体物理力学特性及工程地基处理(Email:songxinghai1982@163.com);通信作者:任永旺(1988-),男,河北盐山人,工程师,研究方向为道路工程及岩土材料力学特性(Email:yw_ren@163.com)。
