砂土的密度相关状态参量的划分及分析  

Classification and analysis of density-dependent state parameters for sand

作　　者：姚仰平[1] 陈凯[1] Yao Yangping;Chen Kai(Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学,北京100191

出　　处：《土木工程学报》2023年第9期116-124,共9页China Civil Engineering Journal

基　　金：国家自然科学基金(51979001);国家重点研发计划(2018YFE0207100)。

摘　　要：土的密度与强度、变形紧密相关,应将密度或密度相关的物理量作为状态参量反映其对应力-应变关系的影响。将状态参量按其作用特点划分成初始孔隙比e0、基于正常压缩线NCL的相对孔隙比γ或超固结比OCR、基于临界状态线CSL的相对孔隙比ψ和基于动态各向异性压缩线ACL的相对孔隙比ξ,并分析了这4种状态参量之间的联系与区别。论证了砂土存在唯一的NCL,其初始点与CSL重合。状态参量ξ以涵盖NCL、CSL的各向异性压缩线ACL为参考线,修正了状态参量ψ不适用于等向压缩、K0压缩等应力路径的问题。基于CSUH模型,分析不同应力路径下状态参量ψ和ξ对计算结果的影响。结果表明:与状态参量ψ相比,选用状态参量ξ条件下的CSUH模型计算的应力-应变关系更适用于各种复杂的应力路径。Strength and deformation of soil is closely related to its density,so density or density-related physical quantity should be considered as a state parameter to reflect its influence on stress-strain relationship.Hence,according to their characteristics,the state parameters are divided into initial porosity ratio e_0,relative porosity ratioγbased on normal compression line or overconsolidation ratio OCR,relative porosity ratioψbased on critical state line and relative porosity ratioξbased on dynamic anisotropic compression line,and the relationship and difference between the state parameters are analyzed.It is proved that sand has a unique NCL and its initial point coincides with CSL.The state parameterξtakes the anisotropic compression line covering NCL and CSL as the reference line,and corrects the problems that the state parameterψis not applicable to isotropic compression,K_0 compression or other stress paths.Based on CSUH model,the influence of state parametersψandξon the calculation results under different stress paths is analyzed.The results show that compared with the state parameterψ,the stress-strain relationship calculated by CSUH model with the state parameterξis more suitable for various complex stress paths.

关 键 词：砂土 孔隙比 状态参量 参考线 CSUH模型 

分 类 号：TU441[建筑科学—岩土工程]