資源描述：
《論土體應力應變關系曲線類型和臨界狀態(tài)》由會員上傳分享，免費在線閱讀，更多相關內(nèi)容在行業(yè)資料-天天文庫。
1、第30卷第1期重慶建筑大學學報Vol.30No.12008年2月JournalofChongqingJianzhuUniversityFeb.2008論土體應力應變關系曲線類型和臨界狀態(tài)11,2周葆春,王靖濤(1.信陽師范學院建筑工程系,河南信陽464000;2.華中科技大學土木工程與力學學院,湖北武漢430074)摘要:為探討應力歷史對土體本構關系的影響,進行了一系列正常固結土和超固結土的排水剪切常規(guī)三軸壓縮試驗,對比具有不同應力歷史的土體應力應變關系曲線發(fā)現(xiàn),對于體應變,超固結比是決定性因素,而體應變對固結壓力不太敏感。對于抗剪能力,固結壓力是決定性因素,超固
2、結比的影響也不可忽略,超固結比決定了是應變強化還是應變軟化,且決定了應變軟化的程度,但試樣最終會達到一個統(tǒng)一的臨界狀態(tài),具有大體相同的殘余強度。根據(jù)塑性體應變與塑性剪應變之間的相互作用原理闡明,土體變形過程中,塑性體應變的變化控制了剪切抗力的升降,從而決定了土體應力應變關系曲線的類型;臨界狀態(tài)實際上是一個純粹剪切變形過程,其中不發(fā)生塑性體應變與塑性剪應變之間的相互作用,壓硬性、剪脹性、應力路徑相關性統(tǒng)統(tǒng)消失,它與以前所經(jīng)歷的應力歷史無關。關鍵詞:土體本構關系;臨界狀態(tài);應力歷史;相互作用原理;超固結比;固結壓力;應變強化;應變軟化中圖分類號:TU43文獻標志碼:A
3、文章編號:100627329(2008)0120063205OntheTypeofStress-strainRelationCurvesandtheCriticalStateforSoils11,2ZHOUBao2chun,WANGJing2tao(1.DepartmentofArchitecturalEngineering,XinyangNormalUniversity,Xinyang464000,P.R.China;2.SchoolofCivilEngineering&Mechanics,HuazhongUniversityofScience&Technolo
4、gy,Wuhan430074,P.R.China)Abstract:Inordertodiscusstheinfluenceofstresshistoryontheconstitutiverelationsforsoils,aseriesofdrainedconventionaltriaxialcompressiontestsfornormallyconsolidatedandoverconsolidatedclayshavebeencarriedout.Itisfoundthroughcomparingthestress-strainrelationcurves
5、underthedifferentstresshistoriesthattheoverconsolidatedratioisthedeterminingfactorforvolumetricstrain.Thevolumetricstrainislesssensitivetoconsolidationpressure,however.Fortheshearcapacity,theconsolidationpressureisthedeterminingfactor,buttheinfluenceoftheoverconsolidatedratiocannotben
6、eglectedsinceitdetermineswhethertherewillbestrainhardeningorstrainsofteningaswellasthegradeofstrainsoftening.Despitethat,thesoilspecimenswillfinallyreachaunifiedcriticalstateandapproximatelythesameresidualstrength.Accordingtotheprincipleofinteractionbetweenplasticvolumetricandshearstr
7、ains,themechanismofgeneratingtwotypesofstress-strainrelationcurvesforclaysisexplained.Itisshownthatthecriticalstateisapureprocessofshearingdeformationinwhichtheinteractionbetweenplasticvolumetricandshearstrainscompletelydisappears.Thecriticalstateisindependentofthepreviousstresshistor
8、y.Key
