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1、第36卷第2期地球科学与环境学报Vol?36No?22014年6月JournalofEarthSciencesandEnvironmentJune2014文章编号:1672G6561(2014)02G0135G08投稿网址http://jese.chd.edu.cn/基于结构性及各向异性的软黏土变形性状试验柳艳华,谢永利(长安大学公路学院,陕西西安710064)摘要:针对结构性和各向异性两大要素对天然软黏土变形性状的影响,对上海天然沉积软黏土进行一维固结试验、K0固结试验以及三轴不排水剪切试验.结果表明:上海天然沉积软黏土具有明显的结构性及各向异性特
2、征;压缩特性在结构屈服破坏前后存在显著差别,具有结构性软黏土所特有的分段特征;不同初始固结应力下的等压及偏压固结不排水应力路径曲线最终都趋近于同一临界状态;在初始有效固结应力低于软黏土的结构屈服应力时,应力应变曲线呈应变软化型,随着初始有效固结应力的增加,当其超过结构屈服应力后,应力应变曲线逐渐呈现硬化型特征;在初始有效固结应力相同且低于结构屈服应力的前提下,偏压固结模式所对应的不排水剪切峰值强度高于等压固结模式,且屈服后的应变软化程度相较于等压固结模式更高;在不排水剪切强度达到峰值后,等压和偏压固结模式下的应力应变曲线逐渐趋于重合;在初始有效固结应
3、力相等的情况下,等压固结模式下产生的孔隙水压力较偏压模式下要高.关键词:岩土工程;软黏土;固结试验;结构性;各向异性;变形中图分类号:P642.13;TU41文献标志码:ATestonDeformationCharacterofSoftClayBasedonStructureandAnisotropyLIUYanGhua,XIEYongGli(SchoolofHighway,Chang?anUniversity,Xi?an710064,Shaanxi,China)Abstract:Inordertofindtheinfluenceofstructur
4、eandanisotropyondeformationcharacterofnaturalsoftclay,oneGdimensionalconsolidationtest,K0consolidationtestandtriaxialundrainedsheartestwerecarriedoutforsoftclayfromnaturalsedimentationinShanghai.TheresultsshowthatthepropertiesofsoftclayfromnaturalsedimentationinShanghaiarechara
5、cterizedbystructureandanisotropy;thecompressionpropertiesaresignificantlydifferentbeforeandafterstructuralyielding,andthecompressioncurveisdividedintotwopartsasstructuralsoftsoil;theundrainedstresspathcurveswithdifferentinitialconsolidationstressesfinallyapproachthesamecritical
6、stateunderisotropicandanisotropicconsolidationmodes;wheninitialeffectiveconsolidationstressislowerthanstructuralyieldingstressofsoftclay,thestressGstraincurveisstrainsoftening,andwhentheinitialstressishigherthantheyieldingstress,thecharacteristicofstressGstraincurveisgraduallyh
7、ardeningwiththeincreaseoftheinitialstress;whentheinitialstressesarethesame,andarelowerthantheyieldingstress,thepeakofundrainedshearstrengthunderanisotropicconsolidationmodeishigherthanthatunderisotropicconsolidationmode,andthestrainsofteningafteryieldingishigherthanthatunderiso
8、tropicconsolidation收稿日期:2014G01G15基金项目:国家自然科学基金项目(5120