資源描述:
《河海大學(xué)土力學(xué)課件》由會員上傳分享,免費在線閱讀,更多相關(guān)內(nèi)容在教育資源-天天文庫。
1、第六章土壓力河海大學(xué)巖土工程研究所ResearchInstituteofGeotechnicalEngineering,HohaiUniversityChapter6EarthPressure第一節(jié)概述Introduction土壓力概念Whatisearthpressure?土壓力種類:Typesofearthpressure靜止土壓力:EarthpressureatrestWhatisearthpressure?第一節(jié)概述IntroductionEarthpressure:Thepressureap
2、pliedonaretainingwallfromsoil第一節(jié)概述Introduction主動土壓力Activeearthpressure被動土壓力Passiveearthpressure靜止土壓力EarthpressureatrestTypesofearthpressure?第一節(jié)概述Introduction主動土壓力Activeearthpressure:Thewallmovesawayfromthesupportedsoil,andthehorizontalsoilpressuresarere
3、fereedtoasactivepressure.Thesoilisinactivestate.被動土壓力Passiveearthpressure:Thewalliscausedtomovetowardsthesoilbeingsupported,andthehorizontalsoilpressuresarerefereedtoaspassivepressure.Thesoilisinpassivestate.靜止土壓力Earthpressureatrest:Thewallisrigidanddoe
4、snotyield,thatisthereisnomovementtakingplace,thehorizontalsoilpressuresaresaidtobeat-restpressure.Thesoilisinat-reststate.Typesofearthpressure?主動極限平衡狀態(tài):Activestate:plasticequilibriumwithlateralexpansiontakingplace.被動極限平衡狀態(tài):Passivestate:plasticequilibriu
5、mwithlateralcompressiontakingplace.靜止平衡狀態(tài):At-reststate:elasticequilibriumwithnolateralstraintakingplace.第一節(jié)概述IntroductionUndernaturalconditionsofdeposition,withsemi-infiniteextent,thereisanegligibleamountofhorizontalstrain,thesoilissaidtobeinanat-restst
6、ate(orK0state),andthehorizontaleffectivestressis:WhereK0=coefficientofearthpressureatrest.At-restearthpressure?Theresultantthrustisequaltotheareaofthepressuredistributiondiagram,I.e.第二節(jié)朗肯土壓力理論Rankine’stheoryActiveearthpressureincohesionlesssoilsSmoothve
7、rticalback,horizontalsurfaceThewallmovesawayfromtheearthfill,VerticalstressismajorprincipalstressSoilinstateofplasticequilibriumKaiscoefficientofactiveearthpressure第二節(jié)朗肯土壓力理論Rankine’stheoryActiveearthpressureincohesionlesssoilsPressuredistributionAunif
8、ormsurchargeload(q)isappliedoverthewholesurfaceThewallmovesawayfromtheearthfill,Verticalstressismajorprincipalstress第二節(jié)朗肯土壓力理論Rankine’stheoryActiveearthpressureincohesionlesssoilsTheresultantthrustisequaltotheareaofthepressuredis