基于NMR的膨润土干燥过程中孔隙水状态研究  

Research on the Pore Water State During the Drying Process of Bentonite Based on NMR

作　　者：王书齐 杨文洲 阳明辉 田慧会[2] WANG Shuqi;YANG Wenzhou;YANG Minghui;TIAN Huihui(Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin University of Technology,Guilin 541004,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China)

机构地区：[1]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004 [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,湖北武汉430071

出　　处：《洛阳理工学院学报（自然科学版）》2024年第4期18-23,共6页Journal of Luoyang Institute of Science and Technology：Natural Science Edition

基　　金：国家自然科学基金面上项目(42072312);国家自然科学基金重点项目(51939011).

摘　　要：为探究GMZ膨润土在干燥过程中孔隙水的演化过程及土-水作用的动力学特性,基于核磁共振技术测量得到了土体在干燥过程中的T_(2)分布曲线及二维T_(1)-T_(2)谱图。通过干燥过程中孔隙水的T_(2)分布曲线结合SWCC描述了土体孔隙水的演化规律,在干燥过程中,土体中孔隙水从化学势较高的大孔隙到化学势较低的小孔隙依次排出。通过二维T_(1)-T_(2)相关测试,基于核磁共振弛豫色散模型确定了干燥过程中水分子在土体颗粒表面的停留特征时间τs和表面亲和系数等表面动力学参数,随着干燥过程的进行,水分子的表面停留特征时间τs随着水势的降低而增加,土体颗粒表面对水分子的吸附性增强,水分子的活动度降低。In order to investigate the evolution process of pore water and the kinetic properties of soil-water interaction during the drying process of GMZ bentonite,the T_(2) distribution curve and two-dimensional T_(1)-T_(2) spectrum of the soil were measured using nuclear magnetic resonance(NMR)technology.The evolution law of pore water in the soil during the drying process was described by combining the T_(2) distribution curve with the soil water characteristic curve(SWCC).The study reveals that during the drying process,pore water in the soil is discharged from larger pores with higher chemical potential to smaller pores with lower chemical potential.Through the two-dimensional T_(1)-T_(2) correlation test,the surface residence time(τs)and surface affinity coefficient of water molecules on the soil particles during the drying process were determined based on the Broadband Proton Pulses(BPP)model and the NMR two-dimensional diffusion model.The results show that during the drying process,the surface residence time(τs)of water molecules increases with the decrease of water potential,indicating enhanced adsorption of water molecules on the soil particle surface and decreased mobility of water molecules.

关 键 词：核磁共振技术 膨润土 二维T 1-T 2谱图 孔隙水 土-水作用 

分 类 号：TU443[建筑科学—岩土工程]