土力学课件第六章土压力

第六章土压力河海大学岩土工程研究所ResearchInstituteofGeotechnicalEngineering,HohaiUniversityChapter6EarthPressure 第一节概述Introduction土压力概念Whatisearthpressure?土压力种类：Typesofearthpressure静止土压力：Earthpressureatrest Whatisearthpressure?第一节概述IntroductionEarthpressure:Thepressureappliedonaretainingwallfromsoil 第一节概述Introduction主动土压力Activeearthpressure被动土压力Passiveearthpressure静止土压力EarthpressureatrestTypesofearthpressure? 第一节概述Introduction主动土压力Activeearthpressure:Thewallmovesawayfromthesupportedsoil,andthehorizontalsoilpressuresarerefereedtoasactivepressure.Thesoilisinactivestate.被动土压力Passiveearthpressure:Thewalliscausedtomovetowardsthesoilbeingsupported,andthehorizontalsoilpressuresarerefereedtoaspassivepressure.Thesoilisinpassivestate.静止土压力Earthpressureatrest:Thewallisrigidanddoesnotyield,thatisthereisnomovementtakingplace,thehorizontalsoilpressuresaresaidtobeat-restpressure.Thesoilisinat-reststate.Typesofearthpressure?主动极限平衡状态:Activestate:plasticequilibriumwithlateralexpansiontakingplace.被动极限平衡状态:Passivestate:plasticequilibriumwithlateralcompressiontakingplace.静止平衡状态:At-reststate:elasticequilibriumwithnolateralstraintakingplace. 第一节概述IntroductionUndernaturalconditionsofdeposition,withsemi-infiniteextent,thereisanegligibleamountofhorizontalstrain,thesoilissaidtobeinanat-reststate(orK0state),andthehorizontaleffectivestressis:WhereK0=coefficientofearthpressureatrest.At-restearthpressure?Theresultantthrustisequaltotheareaofthepressuredistributiondiagram,I.e. 第二节朗肯土压力理论Rankine’stheoryActiveearthpressureincohesionlesssoilsSmoothverticalback,horizontalsurfaceThewallmovesawayfromtheearthfill,VerticalstressismajorprincipalstressSoilinstateofplasticequilibriumKaiscoefficientofactiveearthpressure 第二节朗肯土压力理论Rankine’stheoryActiveearthpressureincohesionlesssoilsPressuredistributionAuniformsurchargeload(q)isappliedoverthewholesurfaceThewallmovesawayfromtheearthfill,Verticalstressismajorprincipalstress 第二节朗肯土压力理论Rankine’stheoryActiveearthpressureincohesionlesssoilsTheresultantthrustisequaltotheareaofthepressuredistributiondiagram,I.e.theareaoftrapeziaThelineofactionofPapassesthroughthecenteroftheareaofthetrapezia Thewallmovestowardstheearthfill,Verticalstressisminorprincipalstress第二节朗肯土压力理论Rankine’stheoryPassiveearthpressureincohesionlesssoilsH/3KpiscoefficientofpassiveearthpressurePassiveearthpressure Verticalstressisminorprincipalstress第二节朗肯土压力理论Rankine’stheoryPassiveearthpressureincohesionlesssoilsKpiscoefficientofpassiveearthpressureTheresultantthrustisequaltotheareaofthepressuredistributiondiagramThelineofactionofPppassesthroughthecenteroftheareaofthepressuredistributiondiagram 第二节朗肯土压力理论Rankine’stheoryActiveearthpressureincohesivesoilsAssuming:Tensioncrackdepth:Totalpassiveresistanceforce: 第二节朗肯土压力理论Rankine’stheoryActiveearthpressureincohesivesoilsAssuming:Tensioncrackdepth:(c)(d)IfZ0<0,thencase(d);IfZ0>0,thencase(c); 第二节朗肯土压力理论Rankine’stheoryActiveearthpressureincohesivesoils(c)(d)IfZ0>0,thencase(c);IfZ0<0,thencase(d);PaPa 第二节朗肯土压力理论Rankine’stheoryPassiveearthpressureincohesivesoils 第二节朗肯土压力理论Rankine’stheoryPassiveearthpressureincohesivesoils Activeearthpressureincaseofgroundwater第二节朗肯土压力理论Rankine’stheoryTheresultanthorizontalthrust: 第二节朗肯土压力理论Rankine’stheoryActiveearthpressureinstratifiedsoil12Layer1Layer2 谢谢！ThankYou!-------------结束TheEND------------欢迎提出意见或建议 总结SummaryToday,inthefollowinghoursIamgoingtointroducechapter6usingEnglish.MyspokenEnglishisnotsogood.ThisisthefirsttimethatIhavehadaclassinEnglish.Itisreallyachallengingtaskforbothyouandme.IamnotsurewhetherIcansuccess,butIwilldomybesttomakeyouunderstandwhatImean.Ihopeallofyousupportme.