,asshownbythedashedlineinFig..ThestructurewasalsomodeledasanisotropicplatemodelwithauniformbendingstiffnessofEI/B=.Nm/m,whichcorrespondstothelongitudinalbendingstiffnessofthegeneralarea.Safetyassessmentofthebreakwater.EnvironmentaldesignconditionsThe-yearreturnwaveheightandthe-yearreturngroundaccelerationweretakenastheenvironmentaldesignconditionsforthebreakwater.Thesignificantdesignwaveheightandsurning,andthetransmittedwaveheightswhenthebreakwaterisintactorisdamaged,arethencalculated.Ahydroelasticresponseanalysisofapontoon-typeVLFSisperformedtofindthewave-inducedinternalforces.Theultimatebendingandshearstrengthsofthefloatingstructurearecalculatedusingtheidealizedstructuralunitmethod(ISUM)andFEM,respectively.Fromtheseresults,theprobabilityoffailureofthefloatingstructureinrelationtothedamagetobreakwateriscalculated.ThestructuralsafetyoftheVLFSisassessedbyacomparisonwiththetargetsafetylevelproposedfortheVLFS.Itisalreadypossibletoanalyzethehydroelasticresponseofapontoon-typeVLFSsurroundedbyagravity-typebreakwater.Asthefirststepinthisstudy,however,thebreakwaterandthefloatingstructurearetreatedseparately；i.e.,thetransmittedwaveheightandthewaveloadsonthebreakwaterareestimatedwiththedesignformulaegivenintheTechnicalStandardsforPortandHarbourFacilitiesinJapan,andthehydroelasticresponseofthefloatingstructureisanalyzedinrelationtotheestimatedtransmittedwaveheightasanincidentwaveheight,neglectingtheeffectofthebreakwater.Fig..Pontoon-typeVLFSsurroundedbybreakwatersFig..Crosssectionofacaisson-typebreakwaterFig..Crosssectionofthefloatingstructure.aGeneralarea；brunwayareaVLFSmodelThefloatingairportmodel(Fig.),designedbytheTechnicalResearchAssociationofMega-Float,Japan,isusedasanexample.Caisson-typebreakwaters(Fig.)arelocatedontheeast,south,andwestsides.Thewaterdepthismatthesouthbreakwaterandmattheeastbreakwater.Thefloatingstructureconsistsofadeck,abottom,andinternalbulkheads(longitudinalgirdersandtransversefloors)inagrillpattern.Figureshowscrosssectionsofonebetween-girderspaceinthegeneralareaandtherunway.Alongitudinalstiffeningsystemisemployedforthedeckandbottomstructuresasinconventionalships.Thereisnotransversecarlingattachedtothedeckandbottomplatingtopreventalocalpanelbuckling.Forthehydroelasticresponseanalysis,afloatingstructurewithaconvexareaforapassengerterminalwasidealizedasarectangularplanarshapewiththeequivalentplanearea,asshownbythedashedlineinFig..ThestructurewasalsomodeledasanisotropicplatemodelwithauniformbendingstiffnessofEI/B=.Nm/m,whichcorrespondstothelongitudinalbendingstiffnessofthegeneralarea.Safetyassessmentofthebreakwater.EnvironmentaldesignconditionsThe-yearreturnwaveheightandthe-yearreturngroundaccelerationweretakenastheenvironmentaldesignconditionsforthebreakwater.Thesignificantdesignwaveheightands前波周期，这是根据Tanimotoetal实验来。JONSWAP谱提供了完整和毁坏防波堤情况：/exp.expfTppsprfTfTHfs....ln...rspppTTTff.,/pff参数由TOKYOBAY观察结果得出：,.,..波谱定向分布由从以下得出：,cos.xxG/x/x获得可能最大波峰分布情况程序在附录A中给出。.破坏功能在大幅度弯曲地方，要对弯剪应力进行检验，在波周期为.—.s时剪应力最大。纵波方向弯曲崩溃截面坐标（x=m，y=m），纵波方向剪力破坏截面坐标（x=m，y=m），横波方向弯距破坏截面坐标（x=m，y=m），横波方向剪力破坏截面坐标（x=m，y=m）。扬式模量E和压应力σy为变量，变化系数为.。连接结构弯剪破坏可由下式表示：,WYuMMEMZ,wYuFFEFZMu和Fu为极限弯剪强度，Mw和Fw分别为弯距和剪力强度。对于中心压力，静荷载要比波压力小，所以仅考虑波浪荷载。因为水面有反射，波浪引起荷载，Mw和Fw既是结构强度又是波浪要素，为了检查扬式模量不确定影响，波浪引起力分布情况可行性分析用一维模式，见附录B。研究发现，因扬式模量不确定性影响可以忽略，所以，在估计波压力时扬式模量可以视为不重要。.可行性分析周期为年浮式结构破坏可能性计算：damagedfbfactfbfsfPPPPP_int_其中Pbf是防波堤倾倒可能性，Psf-intact和Psf-damaged分别是有完整和破损时防波堤情况下浮式结构毁坏可能情况。Psf-cond可用下式计算：ssHsssfscondfdHHfHPP_Psf(Hs)是波高Hs时结构破坏可能性，fH(Hs)是密度对在有完整和毁坏防波堤时传播波高影响。Pfs(Hs)由下式计算,SsfHPMwMuMwMu.技术经济效益指标体系Suzuki讨论了大型浮式结构技术经济效益，如大规模国际机场。首先，在日本这类指标体系有许多体系如交通运输，事故和自然灾害，都用事故发生率检验和表示（FAR，每亿事故数量）。然后，考虑大型浮式结构特点，如公共用途和自然灾害，还有显而易见错误，-值是由大型浮式结构每年破坏总可能性得到。和现在由ISSC调查失去生命力危险指标相比，计划值和效益指标在医院，学校，和其他公共设施等方面是同步。这里，-用于评定大型浮式结构安全性，它是每年容许破坏可能。.安全检验破坏条件、每年和年一遇破坏可能性，纵向波计算都由表格给出。每年破坏可能比弯剪指标要小多。横波结果由表给出。弯曲破坏可能情况在防波堤破坏之后是非常大。相应年破坏可能性是.-。这表明当当前结构没有防波堤时，指标就没有满足。然而，整体破坏可能包括防波堤满足指标。表横波剪切破坏可能比纵波小。这是因为横波受剪区比较大，顶面比底面窄。相似大规模弯距包括纵波和横波，在纵向结构系统中横波弯曲强度比纵波弯曲强度小（图）。表从这些结果可以判断出大型浮式结构考虑情况中，大部分破坏是因为横向弯曲，和相应破坏可能，包括防波堤作用，要满足技术指标。.结论评定有重力式防波堤趸船式大型浮式结构结构安全结果计算出来包括假定防波堤破坏。结果总结如下：）估计防波堤翻转倾倒可能性和密度对传播中波高影响，波高对整体和破坏防波堤影响。）水波反射分析和对大型浮式结构极限强度分析。因为大型浮式结构考虑了纵波和横波，整个横截面极限弯曲强度可以由中心截面破坏整体结构破坏情况来估计。）计算浮式结构破坏可能性方法要考虑防波堤破坏。）大型浮式结构大部分是因为横波弯曲作用破坏。当防波堤影响满足日本安全指标时其他建筑物相应破坏性很小。附录A获得最大波引起力分布方法波最大值引起力表示如下expMvwwoMMF（A）标准偏差σMw用波谱计算，考虑到波分散S(f)G(Χ)，一般方式下传送作用H(f,Χ)。密度对波最大值影响作用wonwowdMdFMFnMf/max（A）假定小时为一个周期，一个波平均周期为Tm，n是由式n=/Tm得到。附录B结构强度对横截面可能力分布影响分析解决水面反射用一维大型浮式结构模型，由Tsubogo和Okada得到，扬式模量E不确定影响，最大波弯距可能分布情况。密度影响fmax(Mw)由下式dEEfEMfMfEwoowmaxmax（B）这儿fmax(Mw|E)是固定值E时密度可能作用。表B比较了在不考虑E不确定时各种波弯距作用。各种不同波距差别不超过。因此，扬式模量就被用于计算不同波波压力。urning,andthetransmittedwaveheightswhenthebreakwaterisintactorisdamaged,arethencalculated.Ahydroelasticresponseanalysisofapontoon-typeVLFSisperformedtofindthewave-inducedinternalforces.Theultimatebendingandshearstrengthsofthefloatingstructurearecalculatedusingtheidealizedstructuralunitmethod(ISUM)andFEM,respectively.Fromtheseresults,theprobabilityoffailureofthefloatingstructureinrelationtothedamag英文文献翻译Structuralsafetyassessmentofapontoon-typeVLFSconsideringdamagetothebreakwaterMasahikoFujikubo,TaoyunXiao,andKazuhiroYamamuraDepartmentofSocialandEnvironmentalEngineering,HiroshimaUniversity,--Kagamiyama,Higashi-Hiroshima-,JapanJournalofMarineScienceandTechnologyVolume,Number/年月AbstractAstructuralsafetyassessmentofapontoon-typeverylargefloatingstructure(VLFS)surroundedbyagravitytypebreakwaterwascarriedoutforextremewaveconditionsbyconsideringthedamagetothebreakwater.Bendingandshearcollapsesareconsideredtobeafailuremodeofthefloatingstructure,whileoverturningdamagesthebreakwater.Theprobabilityofthebreakwateroverturning,andthetransmittedwaveheightbeforeandafterdamagetothebreakwater,areevaluatedusingdesignformulaeforportandharborfacilitiesinJapan.Theultimatebendingandshearstrengthsofthefloatingstructurearecalculatedbytheidealizedstructuralunitmethod(ISUM)andFEM,respectively.Thecalculatedfailureprobabilityforthefloatingstructureiscomparedwiththespecifiedtargetsafetylevel.Itwasfoundthatthefloatingstructureunderconsiderationismostlikelytofailbybendingintransversewaves,andthatthecorrespondingfailureprobabilitysatisfiesthetargetlevel.Keywords：Pontoon-typeVLFSBreakwaterUltimatestrengthOverturningStructuralreliabilitySafetyassessmenIntroductionApontoon-typeverylargefloatingstructure(VLFS)consistsofseveralsubsystems,suchasafloatingstructure,amooringsystem,abreakwater,accesstoland,andsoon.ToensurethesafetyofaVLFS,asafetyassessmentbasedoncollapsescenariosforthetotalsystemmustbeperformed.Forexample,thesafetyofthefloatingstructuremustbeassessednotonlyforanintactbreakwater,butalsoforadamagedbreakwater.Inthisstudy,astructuralreliabilityanalysisofapontoon-typeVLFSsurroundedbyagravity-typebreakwaterwasperformed.ThebendingandshearcollapsesofaunitwithanI-shapedcrosssection,consistingofadeckflange,abottomflange,andagirderweb,areconsideredasthefailuremodeofthefloatingstructure.Thegravity-typebreakwatermaysufferfromseveraltypesofdamage,suchassinking,sliding,oroverturning.Here,damagebyoverturning,whichincreasessignificantlywithincreasingwaveheight,isconsidered.TheprobabilitydistributionofsignificantwaveheightsinfrontofthebreakwaterisdeterminedbasedonthestatisticsforextremewavesinTokyoBay.Theprobabilityofthebreakwateroverturning,andthetransmittedwaveheightswhenthebreakwaterisintactorisdamaged,arethencalculated.Ahydroelasticresponseanalysisofapontoon-typeVLFSisperformedtofindthewave-inducedinternalforces.Theultimatebendingandshearstrengthsofthefloatingstructurearecalculatedusingtheidealizedstructuralunitmethod(ISUM)andFEM,respectively.Fromtheseresults,theprobabilityoffailureofthefloatingstructureinrelationtothedamagetobreakwateriscalculated.ThestructuralsafetyoftheVLFSisassessedbyacomparisonwiththetargetsafetylevelproposedfortheVLFS.Itisalreadypossibletoanalyzethehydroelasticresponseofapontoon-typeVLFSsurroundedbyagravity-typebreakwater.Asthefirststepinthisstudy,however,thebreakwaterandthefloatingstructurearetreatedseparately；i.e.,thetransmittedwaveheightandthewaveloadsonthebreakwaterareestimatedwiththedesignformulaegivenintheTechnicalStandardsforPortandHarbourFacilitiesinJapan,andthehydroelasticresponseofthefloatingstructureisanalyzedinrelationtotheestimatedtransmittedwaveheightasanincidentwaveheight,neglectingtheeffectofthebreakwater.Fig..Pontoon-typeVLFSsurroundedbybreakwatersFig..Crosssectionofacaisson-typebreakwaterFig..Crosssectionofthefloatingstructure.aGeneralarea；brunwayareaVLFSmodelThefloatingairportmodel(Fig.),designedbytheTechnicalResearchAssociationofMega-Float,Japan,isusedasanexample.Caisson-typebreakwaters(Fig.)arelocatedontheeast,south,andwestsides.Thewaterdepthismatthesouthbreakwaterandmattheeastbreakwater.Thefloatingstructureconsistsofadeck,abottom,andinternalbulkheads(longitudinalgirdersandtransversefloors)inagrillpattern.Figureshowscrosssectionsofonebetween-girderspaceinthegeneralareaandt        英文文献翻译Structuralsafetyassessmentofapontoon-typeVLFSconsideringdamagetothebreakwaterMasahikoFujikubo1,TaoyunXiao1,andKazuhiroYamamura21DepartmentofSocialandEnvironmentalEngineering,HiroshimaUniversity,1-4-1Kagamiyama,Higashi-Hiroshima739-8527,Japan2JournalofMarineScienceandTechnology3Volume7,Number3/2003年1月AbstractAstructuralsafetyassessmentofapontoon

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