考虑状态相关的饱和黏土热弹塑性本构模型  

Thermo-elasto-plastic constitutive model of saturated clay considering state-dependent

作　　者：孙增春 陈萌 肖杨[3,4] 樊恒辉[1,2] SUN ZengChun;CHEN Meng;XIAO Yang;FAN HengHui(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,China;Institute of Geotechnical Engineering,Northwest A&F University,Yangling 712100,China;School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Chongqing University,Chongqing 400045,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,杨凌712100 [2]西北农林科技大学岩土工程研究所,杨凌712100 [3]重庆大学土木工程学院,重庆400045 [4]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《中国科学：技术科学》2024年第10期2030-2041,共12页Scientia Sinica(Technologica)

基　　金：国家自然科学基金(批准号:51922024,52078085);中央高校科研基本业务费(编号:2452022121)资助项目。

摘　　要：在能源地下结构、核废料处置和热法地基处理等能源、环境岩土工程中岩土材料经受复杂的温度环境,保证工程结构的可靠性与安全性,深入了解温度效应下土体的体积变化和剪切特性是十分必要的.为了能够较为全面地反映正常固结和超固结土的热力耦合特性,在临界状态理论和边界面塑性理论框架内,建立了状态相关的饱和黏土热弹塑性本构模型.考虑温度变化对屈服应力和临界状态线的影响,通过屈服面上应力点的状态参数和边界面上像应力点的状态参数来表示硬化参数.状态相关硬化参数的引入,能够兼顾模型简洁性与预测超固结土力学特性能力.模型预测与试验数据的对比分析表明,所建立的模型能够合理反映不同温度下饱和黏土在排水和不排水条件下的剪切特性,包括应变硬化、应变软化、剪胀和剪缩等.同时,非等温条件下的热致体积变形特性也能够得到较好的描述.In energy and environmental geotechnical engineering,such as energy underground structures,nuclear waste disposal,and thermal ground treatment technology,geomaterials are subjected to complex temperature environments.It is necessary to deeply understand the volume change and shear characteristics of soils under temperature effect to ensure the reliability and safety of engineering structures.In order to better reflect the thermo-mechanical characteristics of normal and overconsolidated soils,a state-dependent thermo-elasto-plastic constitutive model of saturated clay is established within the framework of critical state theory and boundary surface plasticity theory.Considering the influence of temperature on yield stress and the critical state line,the hardening parameter is expressed by state parameters of the stress point on the yield surface and the image stress point on the bounding surface.The introduction of state-dependent hardening parameters can balance the simplicity of the proposed model with the ability to predict the mechanical properties of overconsolidated soils.The comparison between the model prediction and the experimental data shows that the established model can reasonably reflect the shear characteristics of saturated clay under drained and undrained conditions at different temperatures,including strain-hardening,strain-softening,dilatancy,and contraction.Meanwhile,the thermally induced volume change behavior under non-isothermal conditions can also be well described.

关 键 词：饱和黏土 温度效应 状态参数 临界状态 本构模型 

分 类 号：TU43[建筑科学—岩土工程]