反映粗粒料应力路径相关性的一种应变硬化模型  

A STRAIN HARDENING MODEL REFLECTING STRESS PATH CORRELATION OF CORASE-GRAINED MATERIALS

作　　者：曹光栩[1] 徐明[1] 宋二祥[1] 

机构地区：[1]清华大学土木工程安全与耐久教育部重点实验室,北京100084

出　　处：《工程力学》2013年第4期83-88,96,共7页Engineering Mechanics

基　　金：国家高技术研究发展计划(863计划)项目(2007AA11Z113);高等学校博士学科点专项科研基金课题(200800031061);国家自然科学基金项目(50978140)

摘　　要：粗粒料已成为山区高填方工程的主要填筑材料,建立能较全面反映其力学特性的本构模型,对高填方工程的模拟分析及安全评价具有重要意义。在已有大型三轴试验研究的基础上,通过将硬化土模型与修正剑桥模型相结合同时引入对数形式的非线性强度参数关系式,建立了一种简便实用的弹塑性本构模型。该模型不仅能考虑应力水平对粗粒料应力-应变关系、体变特性、强度特性的影响,还能较好地反映粗粒料的应力路径相关性,模拟复杂应力状态下的粗粒料的变形特性,并且相关参数通过常规三轴试验即可测定。最后通过与不同应力路径试验结果进行对比,证明了模型的合理性。Coarse-grained materials have become main filling materials of high fill engineering in mountainous areas,and building a constitutive model,which can well reflect its stress-strain behavior,is significant for the simulation analysis and safety evaluation of high fill engineering.On the basis of analyzing large scale triaxial experimental results,a new elastic-plastic model is proposed by combining the hardening soil model and the modified cam-clay model,in which the logarithmic relation of strength parameters of coarse-grained materials is also adopted.The new model can not only reflect the nonlinear deformation behavior,nonlinear strength property,confining stress dependence of stiffness,and dilatancy of coarse-grained materials,but also is capable of considering the stress path correlation and simulating the deformation of coarse-grained materials under complex stress paths.Besides,the model parameters can be defined by conventional triaxial experiments.Finally,the model is validated by comparing with different stress path experimental results on coarse-grained materials.

关 键 词：粗粒料 本构模型 非线性 剪胀性 应力路径 

分 类 号：TU443[建筑科学—岩土工程]