摘要
颗粒型膨润土材料具有颗粒间孔隙、集合体间孔隙和集合体内孔隙等多尺度孔隙结构特征,传统非饱和膨胀土双孔模型(BExM)难以准确描述其宏观力学行为。在现有BExM模型的理论框架基础上,从颗粒型膨润土材料的三重孔隙结构出发,通过双加载屈服面方程和宏微观耦合效应函数表征膨润土颗粒混合物的多尺度孔隙弹塑性变形行为及其相互耦合关系。通过对比试验数据与模型模拟结果发现,模型可较好地描述非饱和颗粒型膨润土材料的膨胀力特征、膨胀变形特征以及宏微观孔隙结构演化规律。
Granular bentonite materials have a multiscale pore structure(i. e., inter-pellet pores, interaggregate pores, and intra-aggregate pores), which makes it difficult for the traditional two-porosity constitutive model to accurately describe the mechanical behavior. In this paper, a constitutive model considering triple-porosity structures was proposed based on the BExM model for unsaturated expansive soils. The elasticplastic deformation behaviors and the coupling effects of multi-scale pore structures were described by two yieldsurface equations and two coupling functions,respectively. A comparison of the measured and predicted results shows that the proposed model could well describe the swelling pressure property, the swelling deformation behavior, and the pore evolution characteristic of unsaturated granular bentonite materials.
作者
张召
倪雪倩
张升
ZHANG Zhao;NI Xueqian;ZHANG Sheng(Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring of the Ministry of Education,Central South University,Changsha 410083,China;School of Geosciences and Info-Physics,Central South University,Changsha 410083,China;School of Civil Engineering,Central South University,Changsha 410083,China)
出处
《同济大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第1期23-30,共8页
Journal of Tongji University:Natural Science
基金
国家自然科学基金(42207227)
湖南省自然科学基金(2022JJ40586)
湖南省科技创新计划(2021RC2004)
中国博士后科学基金(2022M713509)
同济大学岩土及地下工程教育部重点实验室开放基金(KLE-TJGE-B2102)。
关键词
膨润土
非饱和土
本构模型
多尺度孔隙结构
bentonite
unsaturated soil
constitutive model
multi-scale pore structure
