堆石料的亚塑性本构建模及其应用研究

亚塑性本构理论是20世纪中晚期发展起来的一类基于有理力学的新型的连续介质本构建模理论,主要用于刻画无黏性散粒型土体的非弹性、非线性及剪胀（剪缩）性等主要应力应变特性。较详细地介绍了该本构理论的起源、发展和本构方程的一般表述形式,并做相应的数学力学特性分析。在对散粒型土体孔隙比与平均压力及孔隙比与体积应变关系分析研究的基础上,扼要介绍了新近发展的亚塑性模型的重要的建模改进思想。结合分析堆石料的主要工程特性,将能够反映当前亚塑性研究水平的Gudehus-Bauer亚塑性模型做适当改进后首次引入到堆石料的本构建模中,并将其应用到一典型混凝土面板堆石坝的应力变形数值分析中。理论分析和算例应用表明,所改进的Gudehus-Bauer亚塑性模型能够合理反映堆石料的非弹性、非线性、剪胀剪缩性等主要应力、应变特性,且具有本构参数适用范围广的优点。

STUDY ON HYPOPLASTIC CONSTITUTIVE MODELING OF ROCKFILL AND ITS APPLICATION

Hypoplastic constitutive theory,which was originated from the middle and late stage of the 20th century,is a new type of soil constitutive theory based on rational mechanics.Hypoplastic theory can reflect inelasticity,nonlinearity,dilatancy and other main mechanical properties of granular material.The origin and development,general representation of hypoplastic constitutive model are introduced;and mechanical and mathematical analysis is made.Besides,the modeling thought of recently updated hypoplastic models is briefly introduced based on the study of the relation between void ratio and mean pressure and the relation between void ratio and volumetric strain of granular soil.Combining with the analysis of main mechanical properties of rockfill,the Gudehus-Bauer hypoplastic model which can reflect the latest international hypoplastic research level is modified properly and applied to constitutive modeling of rockfill.Finally,the new modified model is used in the hypoplastic numerical analysis of deformation and stress of a typical concrete face rockfill dam.Theoretical analysis and engineering application show that the new updated model can reflect inelasticity,nonlinearity,dilatancy and other main mechanical behaviors of rockfill and has the advantage of wide adaptability of constitutive parameters.