文献翻译，水工建筑物，重力坝.doc

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1、Chapter5StaticandDynamicStressAnalysis第五章静态和动态应力分析5-1.StressAnalysis5-1.应力分析a.General.(1)Astressanalysisofgravitydamsisperformedtodeterminethemagnitudeanddistributionofstressesthroughoutthestructureforstaticanddynamicloadconditionsandtoinvestigatethestructuraladequacyofthesubstruct

2、anceandfoundation.LoadconditionsusuallyinvestigatedareoutlinedinChapter4.(2)Gravitydamstressesareanalyzedbyeitherapproximatesimplifiedmethodsorthefiniteelementmethoddependingontherefinementrequiredfortheparticularlevelofdesignandthetypeandconfigurationofthedam.Forpreliminarydesigns

3、,simplifiedmethodsusingcantileverbeammodelsfortwo-dimensionalanalysisorthetrialloadtwistmethodforthree-dimensionalanalysisareappropriateasdescribedintheUSBureauofReclamation(USBR),“DesignofGravityDams”(1976).Thefiniteelementmethodisordinarilyusedforthefeatureandfinaldesignstagesifa

4、moreexactstressinvestigationisrequired.a.普通方法(1)重力坝的应力分析是用以确定在静态和动态荷载作用下结构的应力分布和大小情况以及验证下部和基础的结构强度，荷载条件通常在第四章作了概述。(2)重力坝的应力分析通过基于满足坝体类型、构造和设计精度要求的近似的简化方法或有限单元法。初步设计时，根据美国垦务局（USBR）颁布的“重力坝设计规范（1976）”，可以使用二维的悬臂梁模型或者三维的模型试验的简化方法。有限单元法通常用于对应力精度要求更高的详细和最终设计阶段。b.Finiteelementanalysis.(1)F

5、initeelementmodelsareusedforlinearelasticstaticanddynamicanalysesandfornonlinearanalysesthataccountforinteractionofthedamandfoundation.Thefiniteelementmethodprovidesthecapabilityofmodelingcomplexgeometriesandwidevariationsinmaterialproperties.Thestressesatcorners,aroundopenings,and

6、intensionzonescanbeapproximatedwithafiniteelementmodel.Itcanmodelconcretethermalbehaviorandcouplethermalstresseswithotherloads.Animportantadvantageofthismethodisthatcomplicatedfoundationsinvolvingvariousmaterials,weakjointsonseams,andfracturingcanbereadilymodeled.Specialpurposecomp

7、uterprogramsdesignedspecificallyforanalysisofconcretegravitydamsareCG-DAMS(Anatech1993),whichperformsstatic,dynamic,andnonlinearanalysisandincludesasmearedcrackmodel,andMERLIN(Saouma1994),whichincludesadiscretecrackingfracturemechanicsmodel.b.有限元分析(1)有限元模型用于线性弹性的静态和动态分析以及坝体与基础相互影响的

8、非线性分析。有限元方法具有模拟具有复杂几何形状和不同