岩土介质孔隙结构参数灰色关联度分析  

The grey correlation degree analysis of pore structure parameters of geotechnical medium

作　　者：许林 张巍[1] 梁小龙[1] 肖瑞[1] 曹剑秋 Xu Lin;Zhang Wei;Liang Xiaolong;Xiao Rui;Cao Jianqiu(School of Earth Sciences and Engineering,Nanjing University,Nanjing,210023,China)

机构地区：[1]南京大学地球科学与工程学院

出　　处：《南京大学学报（自然科学版）》2018年第6期1105-1113,共9页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金重点项目(41230636);国家自然科学基金(40902076);苏州市科技计划(SYG201611)

摘　　要：细观孔隙结构是控制多孔介质渗透率的主要因素之一.采用高分辨率工业显微CT,分别对砂雨法成样南京粉砂、振捣干法成样南京粉砂、鄂尔多斯油砂、自贡砂岩和砂雨法成样玻璃珠扫描成像.三维重构后选取尺寸为300体素的表征单元体(Representative Element Volume,REV),基于最大球算法提取出REV的16种孔隙结构参数,并采用格子波尔兹曼方法计算出各REV渗透率.采用灰色关联度方法,分析了平均配位数、平均孔径、最大/小孔径等16个细观孔隙结构参数对多孔介质渗透率影响的主、次关系及其权重.结果表明,16种孔隙结构参数对渗透率的影响从大到小依次为:孔隙平均体积、孔隙最大体积、平均中值喉道、喉道平均半径、孔隙平均半径、喉道最大半径、平均喉道长度、孔隙最大半径、孔隙率、孔隙最小体积、孔喉平均配位数、孔隙截面积平均形状因子、喉道截面积平均形状因子、孔隙最小半径、孔喉比与喉道最小半径.可为岩土介质细观尺度渗流分析提供参考.Pore structure in meso-scale is one of the main factors controlling the permeability of porous medium.In this paper,we use the high resolution industrial micro-CT to image four kind of specimen,Nanjing silty sand specimen fabricated by pluviation and vibrating-dry methods respectively,Erdos oil sand and Zigong sandstone. Meanwhile,a specimen of 1mm glass bead is used for comparison.We use representative element volume(REV)of 300voxels for the three-dimensional reconstruction.16pore structure parameters of the REVs are extracted based on the Maximal-ball algorithm,and the permeability results of the REVs are calculated using Lattice Boltzeman method.Consequently,we use the grey correlation degree method to analyze 16 meso-scale pore structure parameters,such as average coordination number,average pore diameter,maximal pore diameter and minimal pore diameter,etc.,to obtain their primary and secondary relations and their weights.The results show that the influence degrees of the 16pore-structure parameters,from large to small,are pore average volume,pore maximal volume,mid-value pore-throat,average diameter of pore-throat,pore average diameter,maximal diameter of pore-throat, average length of pore-throat,pore maximal diameter,porosity,pore minimal volume,average coordination of pore-throat,average shape factor of pore sectional area,average shape factor of pore-throat sectional area,pore minimal diameter,pore-throat ratio and minimal diameter of pore-throat.The paper can shed light on the seepage analysis of geotechnical medium in meso-scale.

关 键 词：岩土介质 孔隙结构 灰色关联度 表征单元体 格子波尔兹曼方法 配位数 喉道 

分 类 号：TU411[建筑科学—岩土工程]