考虑相变状态及温度效应的冻结砂土非关联弹塑性本构模型  

Non-associated elasto-plastic constitutive model of frozen sand considering the influence of phase transition state and temperature

作　　者：王钰轲 蒋睿 郭成超 王复明[1,2,3,4] WANG Yuke;JIANG Rui;GUO Chengchao;WANG Fuming(School of Water Conservancy and Transportation,Zhengzhou University,Zhengzhou,Henan 450001,China;Tunnel Boring Machine and Intelligent Operation and Maintenance,Zhengzhou,Henan 450001,China;Provincial and Ministerial Collaborative Innovation Center for Underground Engineering Disaster Prevention and Control,Zhengzhou,Henan 450001,China;School of Civil Engineering,Sun Yat-sen University,Guangzhou,Guangdong 510275,China)

机构地区：[1]郑州大学水利与交通学院,河南郑州450001 [2]隧道掘进机及智能运维全国重点实验室,河南郑州450001 [3]地下工程灾变防控省部共建协同创新中心,河南郑州450001 [4]中山大学土木工程学院,广东广州510275

出　　处：《岩石力学与工程学报》2025年第4期1026-1039,共14页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52109140);中原科技创新领军人才(234200510014);河南省高校科技创新人才支持计划(24HASTIT014)。

摘　　要：冻胀是影响冻土力学性质变化的主要因素,将导致冻土在受剪过程中产生更为显著的应变软化和剪胀特征。为了准确描述冻土的力学特征,引入相变状态概念对冻土的剪胀性进行描述,解决了仅采用临界状态理论难以统一软化和剪胀特征点非同步关系的问题,进一步结合分数阶塑性力学理论对冻土应力–应变的非关联塑性流动规律进行描述,避免了塑性势面的额外构建,并通过引入考虑温度影响的屈服函数描述冻土在不同温度下的力学响应。基于考虑相变的硬化法则和考虑温度影响的屈服条件,提出一种改进的弹塑性本构模型,并用于评价冻结砂土的力学特性,所建立模型将温度效应、相变状态、临界状态以及非关联塑性流动统一在弹塑性力学理论框架中,所有模型参数物理意义明确。最后,通过模拟冻结砂土的应力–应变行为,并与试验数据进行对比验证,结果表明本构模型能够有效捕捉不同温度和围压下冻结砂土的相变特征和应变软化规律。Frost heave is the main factor affecting the mechanical properties of frozen soil,which will lead to more significant strain softening and dilatancy characteristics of frozen soil during the shear process.To accurately describe the mechanical characteristics of frozen soil,this paper introduces the concept of phase transition state concept to describe the dilatancy of frozen soil,solving the problem of difficult to unify the softening and dilatancy characteristic point displacement laws using only critical state theory.Furthermore,by combining the fractional order differentiation,the non-associated plastic flow law of stress-strain of frozen soil is described,avoiding the additional construction of plastic potential surfaces.The mechanical response of frozen soil is described by introducing the yield function considering the influence of temperature.Based on the hardening rule considering phase transformation and the yield condition considering temperature effect,an improved elasto-plastic constitutive model is proposed to evaluate the mechanical properties of frozen sand.The model unifies the temperature effect,phase transition state,critical state and non-associated plastic flow in the theoretical framework of elasto-plastic mechanics,and all model parameters have clear physical meaning.Finally,by simulating the stress-strain behavior of frozen sand,and comparing with the experimental data,the results show that the constitutive model can effectively capture the phase transition and strain softening law of frozen sand at different temperatures and confining pressures.

关 键 词：土力学 临界应力 相变状态 温度效应 非关联塑性流动 冻结砂土 

分 类 号：TU43[建筑科学—岩土工程]