泥沙自然堆积孔隙率计算的试验研究(摘要)
颜旭1，李志威1,2，余国安3，李文哲4
[1.长沙理工大学水利工程学院，湖南 长沙 410114；2.水沙科学与水灾害防治湖南省重点实验室，湖南 长沙 410114；3.中国科学院地理科学与资源研究所，北京 101001；4.深圳市水务(集团)有限公司，广东 深圳 518031]
【摘 要】 泥沙孔隙率是泥沙研究的一个重要物理量。从理论上来说，孔隙率是泥沙粒径的函数，它们两者之间存在某种相关关系。以往针对泥沙孔隙率的研究大多限于定性分析，国内对于孔隙率的研究多集中在混凝土等工程材料，国外则对沉积岩的孔隙率研究较为深入，对泥沙孔隙率与粒径的定量表达式仍缺少报道。本文通过设计室内试验，采用排水体积法测量不同粒径组泥沙、均匀沙、混合沙的自然堆积孔隙率，验证了细颗粒泥沙比粗颗粒泥沙孔隙率大的一般性结论，并通过对试验结果的分析与拟合，给出了均匀沙粒径与其自然堆积孔隙率的经验公式，且两者相关性较好。同时，运用圆球模拟泥沙颗粒的方法计算求得均匀沙的理论孔隙率，其中圆球直径为均匀沙的中值粒径。当均匀沙的中值粒径小于4.5mm时，圆球理论孔隙率与实测孔隙率的相对误差小于3%，得到的理论孔隙率较可靠，圆球模拟泥沙颗粒的方法可行。当均匀沙的中值粒径大于4.5mm时，计算得到的圆球理论孔隙率存在较大误差，圆球模拟泥沙颗粒的方法不可行，需要考虑泥沙的球度等因素。
【关键词】 孔隙率；粒径；均匀沙；混合沙；试验研究
基金项目：国家自然科学基金(91547112；91647118)；湖南省教育厅优秀青年项目(16B010)。
作者简介：颜旭(1994— )，男，湖南岳阳人，硕士，主要从事河流动力学研究。
E-mail：343945801@qq.com
Experimental Study on the Porosity of Sediment in Natural Deposition
YAN Xu1,LI Zhiwei1,2,YU Guoan3,LI Wenzhe4
[1.School of Hydraulic Engineering,Changsha University of Science &Technology,Changsha Hunan Province 410114;2.Key Laboratory of Water-Sediment Sciences and Water Disaster prevention of Hunan Province,Changsha Hunan Province 410114;3.Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 101001;4.Shenzhen Water(Group)Co.,Ltd.,Shenzhen Guangdong Province 518031]
Abstract:The porosity is an important physical quantity in sedimentation studies.The porosity of sediment is almost limited to qualitative analysis and there is few study on the quantitative analysis on relation of sediment porosity and particle size.Using the drainage method in experiments is to measure the porosity of different size groups,uniform and mixed sediment.Results verify that the porosity of fine sediments is generally higher than that of coarse sediments.Meanwhile an empirical formula of calculating the porosity of uniform was obtained by fitting the experimental data.The theoretical porosity of uniform sediment was derived by the packing of spheres to simulate the sediments.If the median size of uniform sediment is less than 4.5mm,the theoretical porosity is reliable that the relative error between the theoretical and measured porosity is less than 3%.
Key words:Porosity;Particle Size;Uniform Sediment;Mixed Sediment;Experimental Study