UH模型系列研究  

Advanced UH models for soils

作　　者：姚仰平[1] 

机构地区：[1]北京航空航天大学交通科学与工程学院,北京100191

出　　处：《岩土工程学报》2015年第2期193-217,共25页Chinese Journal of Geotechnical Engineering

基　　金：国家重点基础研究发展计划(973计划)(2014CB047000);国家自然科学基金项目(11272031)

摘　　要：岩土材料的本构模型是岩土工程学科的重要理论基础。合理的本构模型既能定性地揭示岩土的变形强度机制,也能定量地进行岩土体强度和变形计算。笔者20余年来潜心于土的本构模型研究,取得了以下3个方面的理论成果:1在修正剑桥模型的基础上,通过引入统一硬化(unified hardening,UH)参数,建立UH模型,该本构模型能够反映饱和超固结土的剪缩、剪胀、硬化、软化和应力路径相关性等特性,模型所用土性参数与修正剑桥模型完全相同;2扩展UH模型,使其考虑多种外部因素(温度、时间和基质吸力)、复杂特性(各向异性、结构性和小应变特性)和复杂加载条件(循环荷载、部分排水即渐近状态)等的影响;3提出广义非线性强度准则和满足热力学定律的变换应力三维化方法,从而实现了本构模型的合理三维化。UH模型已被嵌入到数值计算软件中,并被用于分析岩土工程问题。以上研究包括本构建模、强度准则、三维化方法和数值分析等方面,形成了独具特色的岩土本构理论和应用体系。The constitutive model for geomaterials is the important theoretical basis of geotechnical engineering. An advanced constitutive model can qualitatively reveal deformation and strength mechanisms of geomaterials, and also quantitatively calculate the deformation and strength. The author has been devoted to the constitutive model for geomaterials for more than twenty years and obtained the following theoretical achievements:(1) The unified hardening(UH) model is established. Using the same soil parameters with the Cam-clay model, the UH model can describe shear contraction and dilatation, strain hardening and softening as well as stress-path-dependency of saturated overconsolidated clay.(2) The UH model is extended to consider influences of some external factors(temperature, time and suction), complicated characteristics(anisotropy, structural and small-strain properties) and complicated loading paths(cyclic loading, and various drainage conditions, namely asymptotic states).(3) The generalized nonlinear strength criterion and the transformed stress method satisfying the thermodynamic laws are proposed in order to generalize reasonably the constitutive model to the three-dimensional stress space. The UH model has been embedded into the commercial numerical analysis software and applied to the geotechnical engineering analysis. This research framework involves constitutive modeling, strength criterion, generalizing method and numerical analysis, forming a unique constitutive theoretical and applicable system.

关 键 词：土 本构模型 强度准则 三维化 数值分析 UH模型 

分 类 号：TU43[建筑科学—岩土工程]