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简介：Animportantresearchareainoceanographicsurveyingandmappingistoobtainsubmarinetopographybyremotesensingtechnique,especiallybySARimagery.Inthisarticle,problemsrelatedtoSARimageryareanalyzedtoprovidereferencesforthefurtherresearch.

简介：Thispaperaimstoachieveanalysisandexperimentresultsthatrelatetomechanicscapabilityandstructuralparameterofaspecialsaddleshellofrevolution.Theoreticallyspeaking,thesaddleshellofrevolutionconsistsofatoroidalshellandasphericalshell.Theshellssimultaneousequationscanbesolvedwithharmoniousterms.Where,thefundamentalequationscanbesolvedbyasymptoticexponentialperturbationmethod.TheequationsofspecialsolutioncanbesolvedbyHovozhilovsspecialsolution.Thisnewideaisfromastudyofsomeexistingsolutionsofthetoroidalshell.Theresultshavebeenprovedbycomparedwithsomeexperimentalresults.Theexperimentsaimstostudytheeffectcausedbychangeofmaterialparameter,orbychangeofdifferentgeometricdimensionsofthesaddleshell,whichincludethechangeofthickness,thechangeofradiusofshell,andthechangeofribs.Finally,theacceptedproductofthesaddleshellwerereinforcedbyatoroidalribhasbeensubmitted.

简介：在借精确集成方法的想法以后，一个精确集成转移矩阵方法(PITMM)被修改传统的转移矩阵方法建议。海底的壳能是加入了conicalcylindrical球形的壳被建模。由考虑ring-stiffeners的效果，革命的壳的地转移矩阵被PITMM精确地获得。在装配地转移矩阵进一个全部矩阵以后，动态模型被建立解决加入的壳的动态回答。由由修改波浪重叠方法(MWSM)在液体描述健全压力并且沿着加入的壳的顶点线并置点，最后，有限的使硬的海底的壳的结构、声学的回答能被联合PITMM和MWSM预言。现在的方法的有效性被把球形的壳的结构、声学的回答与存在结果作比较验证了。而且，海底的壳的结构、声学的回答上的模型截断，僵硬和厚度的效果被学习。

简介：在过去的地震基于海底的电报的表演，在海床差错运动下面决定电报性能的一个分析方法在这篇论文被建议。首先，海底的电报的地震损坏的普通类型被总结，它包括差错运动，海底的山崩和海床土壤液化导致的海床排水量，等等。损坏类似于观察到跟随陆地地震的埋葬的管道的损坏。2006年12月26日的Hengchun地震被用作案例研究。M7.2地震在20:26北京时间在华南海发生了，并且引起了14国际海底的电报切断并且碎。结果证明建议方法预言类似于在Hengchun地震观察了那的损坏。基于水深度和海底的地震的大小的影响的参量的研究，阻止损坏到海底的电报的反措施被建议。

简介：-Thetemperaturedistributionsobtainedbydifferentmethodsofanalysisforsolvingthermaltransferofreinforcedconcrete(R.C.)submarineoiltanks(RCSOT),includingflatwallmethod,cylinderwallmethodandfiniteelementmethod,arecomparedwiththeexperimentaldataofthermaltransferofRCSOT.Theprecisionandscopeofapplicabilityofdifferentmethodsarediscussed.TheprincipleforselectinganalysismethodforsolvingthermaltransferofRCSOTisgiven.TheanalyticalandexperimentaltemperaturedistributionsshowthatthewallofRCSOTshouldconsistofdoublewallsandemptyspacebetweenthemshouldbefilledwithsandorotherheatinsulationmaterialstoreducethetemperaturedifferenceofthewallandtopreventconcretefromcracking.

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简介：Recentandpaleo-submarinelandslidesarewidelydistributedwithinstrataindeep-waterareasalongcontinentalslopes,uplifts,andcarbonateplatformsonthenorthcontinentalmarginoftheSouthChinaSea(SCS).Inthispaper,high-resolution3Dseismicdataandmultibeamdatabasedonseismicsedimentologyandgeomorphologyareemployedtoassistinidentifyingsubmarinelandslides.Inaddition,depositionmodelsareproposedthatarebasedonspecificgeologicalstructuresandfeatures,andwhichillustratethelocalstressfieldoverentiresubmarinelandslidesindeep-waterareasoftheSCS.TheSCSisoneofthelargestfluvialsedimentsinksinenclosedorsemi-enclosedmarginalseasworldwide.Itthereforeprovidesasetofpreconditionsfortheformationofsubmarinelandslides,includingrapidsedimentaccumulation,formationofgashydrates,andfluidoverpressure.Anewconceptinvolvingtemporalandspatialanalysesistestedtoconstructarelationshipbetweensubmarinelandslidesanddifferenttimescaletriggermechanisms,andthreemechanismsarediscussedinthecontextofspatialscaleandtemporalfrequency:evolutionofslopegradientandoverpressure,globalenvironmentalchanges,andtectonicevents.Submarinelandslidesthataretriggeredbytectoniceventsarethelargestbutoccurlessfrequently,whilesubmarinelandslidestriggeredbythecombinationofslopegradientandoverpressureevolutionarethesmallestbutmostfrequentlyoccurringevents.Insummary,analysisshowsthattheformationofsubmarinelandslidesisacomplexprocessinvolvingtheoperationofdifferentfactorsonvarioustimescales.

简介：Asatransportmeansofoilandgasthesubmarinepipelinehasmanymerits,suchascontinuousdelivery,largeconveyingcapacity,convenientmanagement,etc.Atubewaschoseninourstudytosimulatethesubmarinepipelineintheexperiments.AhighaccuracyinstrumentADVandhighprecisionpoint-typepressuresensorswereusedtomeasuretheparametersoftheflowfield,includingthepressuredistribution,velocitiesatsevencrosssectionsnearthesubmarinepipelinewithfivedifferentclearanceratios,andtwelvedynamicpressurevaluesaroundthepipeline.Thepressuredistributionsandvelocitychangesaroundthepipeunderdif-ferentflowvelocitiesandclearanceratioswereanalyzed.Theseresultsmightbeusefulforfurtherstudyofsubmarinepipelineero-sionandprotection.

简介：Inthispaper,theinfluencedepthsofalllevelsofwindpowerproducedwavesarereckonedaccordingtothemeasuredswayingdegreewhenasubmarinemeetswithaforce11strongtropicalstormandhastosubmerge;Thentheminimumsubmergencedepthisgivenwhenasubmarineisfacedwithweathersystemswithforce≥6windandtheswayingdegreeoflessthan12degreeisassuredasreferenceforasubmarineworkingandsailinginbigstrongwindsandwaves.

简介：基于中国908工程的最近的海底的地形学数据(中国近海海洋的环境全面调查和评价)，我们分析了一般中国近海影响它的发展的海底的地形学的特征和因素。离开中国的海岸的海底的地形学跟随陆地地形学的NW-SE趋势。海底的地形学的坡度与大约0.8%的一个平均坡度从0.2%～1.6%。深度轮廓与海岸变主要平行，并且在河口区域伸出到海。海底的地形学被地质的结构统治，它证明二的典型特征高举并且从北方的二个沉淀事件到向南。与不同沉积环境和复杂水动力学条件相结合的地质的结构生产了能被三种类型描绘的地形学：沉积的盆，压缩高举，和转变形式。在沉积的盆和压缩高举区域，地形学的波动是小的，沉积是有细密纹理的，并且水流流动在一个单个方向，导致有沉积平原的海湾并且在水下累积倾斜，它具有一样的构造起源。转变类型地形学被强壮的波动和混合尺寸沉积描绘粒子，平台和沿海的陡坡和架平原和侵蚀免职地形近海。这是不完全的差错块开发的结果并且重复违反。在免职改革区域(转变形式类型)，地形学有强壮的波动，沉积是粗糙的，潮汐的沙山脉在源自陆地供应的河口和集中地区是开发得好的，并且Holocene沉积是厚的，由潮，河流量，和水流转变了。

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简介：Freespanningpipelinesaresuspendedbetweentwopointsonanunevenseafloor.Thevariationsofstructuralconditions,suchasthechangesinsoilproperty,flowvelocity,axialforceandspanlengthetc.,directlyaffectworkingperformanceofthewholesubmarinepipelinesystem.Butuntilnowfewresearcheshavefocusedonconditionidentificationforfreespan(CIFS).Amethodtoidentifytheoperationalconditionsoffreespanningsubmarinepipelinesbasedonvibrationmeasurementsisproposedinthispaper.Firstly,theill-posednessofCIFSisanalyzedindetail.Secondly,theframeworkforCIFSbasedonthenonlinearkerneldiscriminantanalysis(KDA)isestablished.Thirdly,theinternalstructuralcharacteristicsofnaturalfrequencies,normalizedfrequenciesandfrequencychangeratiosarestudied.AndthentheconditionfeaturevectorforCIFSisextractedbyuseofthevibrationmeasurements.Finally,thevalidityoftheproposedapproachisevaluatedbyacasestudy.Theresultsdemonstratethattheproposedapproachcaneffectivelyidentifyeachconditionoffreespanwhenconditionvariationoccursevenifundermeasurementnoise.ItisconcludedthattheproposedmethodisapromisingtoolforCIFSinrealapplications.

简介：Inmarineengineering,thestrengthofasubmarinesedimentisanindispensableparameterforassessmentofconstruction.Inthisstudy,afree-fallconepenetratornamedIPenwasdevelopedtorealizearapidandefficientmeasurementofsedimentstrength.Theequipmentischaracterizedbymodulardesignandself-containeddataacquisition.Itisequippedwithanaccelerationsensor,awaterpressuresensor,andapiezoconepenetrationtest(CPTu)probe.Itisdesignedtobereleasedfromnearseabedsurfacewithareleaserandthenfallfreelytoprovideahigherpenetrationvelocity.Itsmaximumworkingdepthisapproximately2500mandmaximumpenetrationdepthisapproximately3m.Toderivethecorrelationbetweenpenetrationresistanceandsedimentstrength,acalibratorwasdevisedtodeterminethepenetration-ratefactor.Inaddition,thefactorapplicabletoinsitutestpointswasdeterminedinlaboratoryexperiments.InJune2016,theIPenwastestedinsituintheSouthYellowSea,China,duringasharedvoyagefundedbytheNationalScienceFoundation.Meanwhile,undisturbedcolumnsampleswerecollectedforlaboratorytests.Basedontheinsitutestresults,itwasdemonstratedthattheIPencouldaccuratelyrecordtheworkingstatesofvarioussensorsduringthefreelyfallingcourse.IPentestresultsreliablyreflectedthesedimentstrengthatallthetestingpointswhencomparedwithlaboratorycalibrationtests,insituvanetestsandpenetrationtests,laboratorypenetrationtests,andunconsolidatedandundrainedtriaxialcompressiontests.

简介：1.ObjectiveNaturalgashydratesareconsideredasapotentialalternativefuelresourcetopetroleumandgas(ChongZRetal.,2016),whichcanbeexploitedbymeansofdepressurization,thermalmethod,inhibitorinjection,etc.Forthethermalmethod,gashydratesaredecomposedintowaterandmethanewhenthereservoirisheatedtoabovetheequilibriumtemperatureofgashydrate(LiXetal.,2016).However,thethermalrecoverymethodneedsagreatdealofheat,andthusthefeasibilityofeconomicexploitationisreduced.

简介：SubmarinelandslideshavebeenobservedintheBaiyunDepressionoftheSouthChinaSea.Theoccurrenceofhydratesbelowtheselandslidesindicatesthattheseslopeinstabilitiesmaybecloselyrelatedtothemassivereleaseofmethane.Inthisstudy,weusedasimpleMonte-Carlomodeltodeterminethefirst-orderdeformationpatternofagravitationallydestabilizingslope.Theresultsshowthatastressconcentrationoccursduetohydratedissociationonthenearbyglidesurfaceandontopofagaschimneystructure.Uponthedissolutionofthegashydrate,slopefailureoccursduetotheexcessporepressuregeneratedbythedissociationofthegashydrates.Whengashydratesdissociateatshallowdepths,theexcessporepressuregeneratedcanbegreaterthanthetotalstressactingatthosepoints,alongwiththeforcesthatresistsliding.Initially,thefailureoccursatthetoeoftheslope,thenextendstotheinterior.Althoughourinvestigationfocusedonlyonthecontributionofhydratedecompositiontosubmarinelandslide,thisprocessisalsoaffectedbyboththeslopematerialpropertiesandtopography.

简介：Thestabilityofasubmarinepipelineontheseabedconcernstheflow-pipe-soilcoupling,withinfluentialfactorsrelatedtotheoceanwavesand/orcurrents,thepipelineandthesurroundingsoils.Aflow-pipe-soilcouplingsystemgenerallyhasvariousinstabilitymodes,includingtheverticalandlateralon-bottominstabilities,thetunnel-erosionoftheunderlyingsoilandthesubsequentvortex-inducedvibrations(VIVs)offree-spanningpipelines.Thispaperreviewstherecentadvancesoftheslip-linefieldsolutionstothebearingcapacity,theflow-pipe-soilcouplingmechanismandthepredictionforthelateralinstability,themulti-physicalcouplinganalysisofthetunnel-erosion,andthecouplingmechanicsbetweentheVIVsandthelocalscour.Itisrevealedthatthemechanismcompetitionalwaysexistsamongvariousinstabilitymodes,e.g.,thecompetitionbetweenthelateral-instabilityandthetunnel-erosion.Finally,theprospectsandscientificchallengesforpredictingtheinstabilityofalong-distancesubmarinepipelinearediscussedinthecontextofthedeep-wateroilandgasexploitations.

简介：Thispaperpresentsthedetaildesignconditions,designcriteriaandmethodsaswellasdesignconclusionsoftheprocess,structureandcorrosionoftheproductionflowlinesandhighpressurewaterinjectionlinesinBZ34-2/4oilfieldinBohaiBay.AtpresentthisdesignrepresentsthedesigncapabilityandlevelinthefieldofthesubmarinepipelineengineeringofChina.

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简介：-Acompositepipelineisdefinedasapipelinesystemcomposedofonebigpipeandoneorseveralsmallpipes.Basedonthetheoryofwave-currentinteractionandphysicalmodeltest,thehydrodynamiccharacteristicsofthesubmarinecompositepipelineinwave-currentcoexistingfield(bothregularandirregularwaves)areinvestigated.Theso-called"modifieddiametermethod"isusedforanalyzingthein-finehydrodynamiccoefficientsofthecompositepipeline,whicharewellrelatedtoKCnumber.Thecomparisonoftestdataforregularandirregularwavesshowsthatintheregionof90>KC>20,theresultsinthesetwocasescanbeunified.Theeffectofwaterdepthisanalyzedindetails.TherelationshipsbetweenCD,CMandKC,whicharebasedontheresultsofpresentresearch,maybeusedasareferenceinengineeringdesign.