K_(0)固结结构性黄土的各向异性本构模型  

Critical state constitutive model of K_(0) consolidated structural loess

作　　者：侯乐乐 翁效林[1,2] 崔艺铖 韩巍巍 陈禹勋 HOU Lele;WENG Xiaolin;CUI Yicheng;HAN Weiwei;CHEN Yuxun(Key Laboratory for Special Area Highway Engineering of Ministry of Education,Chang'an University,Xi'an,Shaanxi 710064,China;School of Highway,Chang'an University,Xi'an,Shaanxi 710064,China)

机构地区：[1]长安大学特殊地区公路工程教育部重点实验室,陕西西安710064 [2]长安大学公路学院,陕西西安710064

出　　处：《岩石力学与工程学报》2022年第10期2124-2134,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(U1934213)。

摘　　要：受结构性和初始应力各向异性的影响,原状黄土的力学及变形特征尤为复杂,深入研究原状黄土的本构关系在理论及实际工程应用方面都具有重要意义。在修正剑桥模型的基础上,分析了原状黄土在水、力条件下的结构演化规律,提出了考虑水、力影响的结构性黄土体变方程,通过引入相对应力比和相对临界状态应力比的概念,使模型能够合理描述原状黄土的初始各向异性。进一步采用相关流动法则推导出可同时反映原状黄土结构性和初始应力各向异性的本构模型。当不考虑结构性及初始应力各向异性影响时,模型可退化为修正剑桥模型。通过与已有原状黄土三轴试验结果与模型预测结果的对比可知本文模型能较为合理地描述原状黄土的强度及变形特征。Due to structural and initial stress anisotropy,the mechanical and deformation characteristics of undisturbed loess are particularly complex.It is of great significance to study the constitutive relation of undisturbed loess in theory and practical engineering application.Based on the modified Cam-clay model,the structural evolution law of undisturbed loess under water and force conditions was analyzed in this paper.Furthermore,the volumetric change equation of structural loess considering the effects of water and force was proposed,which can reasonably describe the initial anisotropy of undisturbed loess by introducing the concepts of relative stress ratio and relative critical stress ratio.A constitutive model reflecting both structural and initial stress anisotropy of undisturbed loess was derived further by using the correlation flow rule.When the structural and initial stress anisotropy are not considered,the model can be reduced to the modified Cam-clay model.Compared with the triaxial test results and model prediction results of undisturbed loess,the model in this paper can reasonably describe the deformation behavior of undisturbed loess under water and force conditions.

关 键 词：土力学 结构性黄土 K_(0)固结状态 初始各向异性 应变软化 初始含水率 

分 类 号：TU43[建筑科学—岩土工程]