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简介：Ｔｈｅ　Ｇｒａｎｄｅｓｔ　Ｃａｎｙｏｎ　ｉｎ　ｔｈｅ　ＷｏｒｌｄＴｈｅＧｒａｎｄｅｓｔＣａｎｙｏｎｉｎｔｈｅＷｏｒｌｄ￥ｂｙＹａｎｇＹｉｃｈｏｕＦｏｌｌｏｗｉｎｇｎｕｍｅｒｏｕｓｉｎｖｅｓｔｉｇａｔｉｏｎｓａｎｄｅｘｐｅｄｉｔｉｏｎｓ，ｅｘｐｅｒｔｓ...

简介：ＯｎｔｈｅＮａｍｉｎｇｏｆｔｈｅＹａｒｌｕｎｇＺａｎｇｂｏＣａｎｙｏｎＷＵＺＨＥＮＨＵＡＩｎ１９９７，ＩａｔｅｎｄｅｄｔｈｅＳｅｃｏｎｄＳｅｍｉｎａｒｏｎｔｈｅＣｏｍｐｒｅｈｅｎｓｉｖｅＤｅｖｅｌｏｐｍｅｎｔａｎｄＰｒｏｔｅｃｔｉｏｎｏｆｔｈｅＹ...

简介：Afewhours'drivetookmetoaplacecalledBingzhongluo,thelargestpieceofflatlandinthecanyon,wheretheNujiangRivertakestwoabruptturns,formingthefirstbendontheNujiangRiver,whichisabestknownscenicspotinChina.Atthesideoftheriverthereisatabletofpurewhitemarbleinscribedwithwordspaintedinbrightred,reading:“Bingzhongluo,theShangri-La.”

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简介：TheuseofnarrowcanyontoconstructasmallhydropowerplantinsouthwestChinameansthatthecostofbuildingtheplantwillbecutbyuptotwo-thirds.

简介：Thispaperpresentsastep-by-stepprocedureusingthethree-dimensionalboundaryelementapproachtostudythebehaviorofsemi-circularcanyonsunderseismicshearwaves.TheboundaryelementcodeTDASCallowsutilizationforvariouscanyongeometries,evaluationofconcurrentseismicwavesandcalculationofthegroundmotionsoncanyonsduetoanexcitationatanyarbitrarypointoftheincidentfield.Consideringthewideningratioofthecanyon(includingprismatic,semi-prismaticandnon-prismaticcanyons),wavecharacteristics(wavelength,dimensionlessperiod,direction)andmaximumamplificationpattern,thesolutionwasappliedtocarryoutaseriesofparametricstudies.Itwasshownthatcanyonformcansignificantlyaffectthedisplacementamplification,especiallyatthepointslocatedonitsedges.Byincreasingthewavedimensionlessfrequency(η>1),theamplificationpatternbecomesmorecomplex.Onthebasisoftheresultsfromavarietyofconsideredcases,anewexpressionhasbeenpresentedforthelimitingwavelengthbeyondwhichthewideningofthecanyonwillnothaveamajoreffectonthedisplacementamplification.Toverifythereliabilityoftheproposedapproach,theobtainedresults,expressedintermsofdisplacementamplitude,werecomparedwiththosefromtheavailablepublishedliteratureandareasonablygoodagreementwasobserved.

简介：Thispaperpresents2.5DscatteringofincidentplaneSHwavesbyacanyoninlayeredhalf-spacebytheindirectboundaryelementmethod(IBEM).Thefreefieldresponseiscarriedouttogivethedisplacementsandstressesonthelinewhichformsboundaryofthecanyon.ThefictitiousuniformmovingloadsareappliedtothesamelinetocalculatetheGreen'sfunctionsforthedisplacementsandstresses.Theamplitudesoftheloadsaredeterminedbytheboundaryconditions.Thedisplacementsduetothefreefieldandfromthefictitiousuniformmovingloadshavetobeaddedtoobtainthewholemotion.Thenumericalresultsarecarriedoutforthecasesofacanyoninhomogenousandinonelayeroverbedrock.Theresultsshowthatthe2.5Dwavescatteringproblemisessentiallydifferentfromthe2Dcase,andthereexistdistinctdifferencesbetweenthewaveamplificationbyacanyoninlayeredhalf-spaceandthatinhomogeneoushalf-space.Thereasonsforthedistinctdifferenceareexplored,andtheeffectsofthethicknessandstiffnessofthelayerontheamplificationarediscussed.

简介：二斜角肌的Antiplane反应由嘘波浪的三角形的山和一个半圆柱的峡谷用波浪功能扩大和复杂功能方法被学习。第一，分析模型被划分成三部分，和波浪领域的排水量答案在三个区域基于边界条件被构造。三个领域然后被结合在分享的边界满足连词条件。另外，与半圆柱的峡谷的零压力的条件结合了，为这个问题的一系列无限的代数学的方程被导出。最后，数字例子被提供，地面运动上的不同参数的影响被讨论。

简介：ItmaybesafetosaythatfewplacesonearthcanmatchtheNujiangCanyonintermsofcultural,ethnicandreligiousdiversity.Peopleof14ethnicgroupslivesidebysidepeacefullyinthissouthwestChinaarea,whereatleastfourreligions,plusnumerousfolkbeliefs,coexistinharmony,Fourallthis,plusasurpassingscenicbeautyandauniqueculturalheritage,peopleintheirtensofthousandshavecometosee,toenjoyand,aboveall,tobeinspired.

简介：Toevaluatetheimportanceofthecanyontopographyeffectsonlargestructures,basedonarigidframebridgeacrossa137-m-deepand600-m-widecanyon,theseismicresponseofthecanyonsiteisanalyzedusingatwo-dimensionalfiniteelementmodelunderdifferentseismicSVwaveswiththeassumptionsofverticalincidenceandobliqueincidencetoobtainthegroundmotions,whichareusedastheexcitationinputonthepierfoundationsofthebridgewithimprovedlargemassmethod.Theresultsindicatethatcanyontopographyhassignificantinfluencesonthegroundmotionsintermsofincidentangle.Thepeakgroundaccelerationvaluesvarygreatlyfromthebottomofthecanyontotheuppercorners.UnderverticalincidentSVwaves,attheuppercornersofcanyonthepeakgroundaccelerationsgreatlyincrease;whereasthepeakgroundaccelerationsdiminishatthebottomcornersofcanyon.UnderobliqueincidentSVwaves,theshakingofthecanyonslopeperpendiculartotheincidencedirectionismuchmoreseverethanthatoftheoppositesideofcanyon.Andthegroundsurfacehasbeencharacterizedbylargerdeformationsinthecaseofobliqueincidentwaves.Itisalsoconcludedthatthelowpiersandframeofthecontinuousrigidframebridgearemoresensitivetothemulti-supportseismicexcitationsthantheflexiblehighpiers.Thecanyontopographyaswellastheobliqueincidenceofthewavesbringsthecontinuousrigidframebridgesevereresponses,whichshouldbetakenintoaccountinbridgedesign.