摘要
简单回顾了非饱和土本构模型研究的发展历程,总结了近几年非饱和土弹塑性本构模型最新研究成果,重点介绍了能统一模拟非饱和土水力性状和力学性状耦合的弹塑性本构模型。通过对建立模型过程中的几个核心问题讨论,较详细地说明该类模型的结构、性能以及相关问题。非饱和土水力性状的滞回性用假定存在饱和度弹性区间的弹塑性过程来模拟;该类耦合模型不仅考虑了吸力对非饱和土水力性状和力学性状的影响,还考虑了饱和度对应力-应变关系和强度的影响以及土体变形对土-水特征曲线的影响。用同一套模型参数,耦合模型可统一预测在吸力控制或含水率控制下沿各种应力路径下非饱和土的水力-力学特性,并简单介绍了膨胀性非饱和土的弹塑性本构模型以及耦合模型在有限元数值计算中的应用。
The progress in constitutive models for unsaturated soils is briefly reviewed at first; and then the state of the art of elastoplastic constitutive models for unsaturated soils is summarized. This paper focuses on introducing an elastoplastic model coupling hydraulic and mechanical behaviour of unsaturated non-expansive soils. As an example, a coupled elastoplastic constitutive model proposed recently by the author et al. and its model predictions are shown herein for illustrating the structure of the coupled model and its performance. Hydraulic hysteresis in the soil-water characteristic is modeled as an elastoplastic process with the elastic region of the saturation degree. The effect of change in degree of saturation on the stress-strain-strength behaviour and the effect of change in void ratio on the soil-water characteristics are taken into consideration in the model; in addition to the effect of suction on the hydraulic and mechanical behaviour. By using the same values of the model parameters, hydraulic and mechanical behaviour of unsaturated soils can be consistently predicted under the control of suction or water content along various total stress paths. The elastoplastic constitutive model for unsaturated expansive soils and the application of the coupled model to the finite element computations are introduced in brief.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2009年第11期3217-3231,共15页
Rock and Soil Mechanics
基金
教育部留学回国人员科研启动基金
关键词
非饱和土
弹塑性模型
应力-应变关系
水力特性
耦合
unsaturated soil
elastoplastic model
stress-strain relation
hydraulic behaviour
coupling
