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Like engineers in every major discipline, civil and structural engineers are facing an expanded array of mathematical challenges. Now more than ever, societies are placing a greater emphasis on:

• Environmentalissues – protecting and preserving natural resources

• Sustainability – as the global population grows and the human footprint expands

• Sociallysupportive,intelligentinfrastructure – as societies become more sophisticated and demand greater efficiency and real-time results

For civil and structural engineers, accurate and intelligent system models – and the complex math-ematics that they require – are at the core of meeting these sophisticated, modern challenges. The need to accurately model infrastructure and utilities, environmental systems, urban planning and large architectural projects has never been more critical – and difficult. Engineers are facing unprecedented pressure to get it right the first time under increased regulatory oversight.

Theengineeringcalculationsthatcansolvetheseissuesarecomplexanddifficulttomanage.Itisnolongersufficienttohavethesecalculations,anorgani-zation’sintellectualproperty,lockedawayinspread-sheetsandtraditionalengineeringnotebooks.

Thegoodnewsisthatmathematicaltechnologyhasevolvedtogiveengineerssolutionsthat,ifusedprop-erly,canbeveryeffective.Designandcalculationsoftwaregivescivilandstructuralengineersthetoolstosolvetoday’smostpressingandcomplexproblems,andinnovatelikeneverbefore.

Thisarticlewilldiscussmoderncivilandstructuralengineeringprojectswherecomplexengineeringmathematicshasbeenattheheartofovercomingthesenewchallenges.Specifically,wewilllookatengineerswhoare:

• DesigningsustainablebuildingsliketheShanghaiTowerthatcanwithstandabroadrangeofenviron-mentalconditionsanddisasters

• ProtectingwaterresourcesinVirginia

• WorkingwiththeAustralianAidprogramtocon-structinfrastructurethatcanmeetthedemandsofagingpopulationsandincreasedurbanization

Pushing the Mathematical EnvelopeCasE studiEs in solving ModErn Civil and struCtural EnginEEring CalCulations ChallEngEs

At662meterstall,theShanghaiTower,shownunderconstruc-tionontheleft,willbecomethesecondtallestbuildingonearthuponcompletionin2014..

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the shanghai tower: a Case study in sustainable design

Economicandpoliticalfactorsareputtingpressureonengineersanddesignerstomakedecisionstodaythatwillminimizeenvironmentalimpactsonfuturegen-erations.Sustainabledesignisespeciallyimportantforlargestructures,wherethechallengeistodesignbuildingsthatcanwithstandstheseenvironmentaldisasterswhileminimizingenergyconsumptionandmaterials.

At662meterstall,theShanghaiTowerwillbecomethesecondtallestbuildingonearthuponcompletionin2014.Leaddesigner,PeterWeingarten,knowsfullwellthatittookyearsforengineersjusttofigureouthowtogetsuper-tallbuildingstostandatall.“Onceyougetabove80stories,mostprivatebrokerswilltellyouthattheeconomicsofthebuildingdon’tpanout,becauseyouhavesomanystructuralconsiderationsbecauseofthelateralload,”hesaysinaninterviewwithCleanTechies.

Buttoday,usingadvancedproblem-solvingtech-niquesandengineeringcalculationsoftware,verti-calcitiesliketheShanghaiToweraren’tonlypossible,they’reattheforefrontofthegreenbuildingrevolution.Thestructuresetsanewstandardinsustainabilitybyincludingthefollowingfeatures:

• Windturbinesthatcangenerateupto350,000kWhofelectricityperyear

• Arainwaterrecyclingsystem

• Atwistedshapedesignthatreducesstructuralsteelbymorethan20percent

Weingartenadmitsthatoneofthebiggestchallengeshisteamfacedwasthewindforcenearthetopofthebuilding.Aunique,curvedshapenotonlysolvedtheproblem,butalsocutsteelcostsbynearlyaquarter.“Wewereabletosave25percentofthetonsteeltonnagebynotpresentingabroadfacetothewind,”Weingartenreveals.“Byallowingthewindtoflowaerodynamicallywemitigatedirectlateralpressures.WealsomadeuseoftheDiagridSystem,whichallowsthewindtoflowinanaturalwayinsteadoforthogonallylikewithclassicdesigns.”Traditionallateralloadandforcecalcula-

overcoming Civil and structural Engineering Challenges requires sophisticated Calculations

Advancesinmathcalculationsoftwareensureaccuracyandmitigaterisk.

ChallEngE CalCulations rEquirEd

Designsustainablebuildingsthatcanwithstandenvironmentalfactorsandnaturaldisasters

•Lateralload

•Maximallateralimpulseforce

•Equivalentstaticanalysis

•Responsespectrumanalysis

•Lineardynamicanalysis

•Non-linearstaticanalysis

•Non-lineardynamicanalysis

Conductwatershedstudiestoprotectwaterresources

•Fluidmechanicsandhydrology

•Computationalfluiddynamics

•Fluidstructureinteractions

Examineimpactofpopulationgrowthoninfrastructureandresources

•Rateofnaturalincrease

•Demographictransitionmodeling

•Carryingcapacity

tionsneedtoaccountforcurvatureandotherproper-tiesoftheaerodynamicstructure,whichrequiresmoreadvancedandcomprehensivecalculations.

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Inadditiontoitsspecial,aerodynamicshape,theShanghaiTowerincorporateswhat’scalledanoutrig-gertrussevery14floorsforgreatersupport.Eachoutriggertruss“actslikeyourshoulder”tobroadenthebaseofthebuilding,accordingtoWeingarten.Struc-turesthatinvolvereinforcedsupportsystems,suchasoutriggertrusses,typicallyrequireintensivelinearandnonlinearstaticanddynamicanalysisofthecompletestructureanditscomponents.Usinganengineeringsoftwarepackageisessentialtogettingthisright.

Becausethebuildingwillbesturdier,thedesignerswereabletoengineeradditionalsustainabilityfea-tures,suchasadoubleskin.AccordingtoGensler’sDanWiney,whilethedoubleskinis“anodetothecity’shistoricopencourtyards,”thedesignhasdefinitesustainabilitybenefits:“Thecontinuousglassskinwilladmitthemaximumamountofdaylightintotheatriums,reducingtheneedforartificiallighting,”Wineysays.“Theglassalsohasaspectrallyselectivelow-Ecoatingthatwillhelpreduceheatingandcoolingloads.”

AsWeingartenexplains:

“Webuiltaspacebetweentheinnerskinandwhat’sreallythefacadeofthebuildingtocreateaseriesofverticalparksthatactasathermalbufferbetweenthefaceofthebuildingandtheoutsideworld.Insteadofhavingacompletelyopaquebuildingyouhaveaclearone.Mostskyscrapersareessentiallyopaquetotheoutsidebecauseofthehighreflectivityoftheirwindows,anecessitytolimitsolarheatgain.”

Channel Erosion quantification: a Case study in Watershed Protection

Whilesomeengineersfocusonthesustainabilityofman-madeconstructions,othersareworkinghardtomaintainthesustainabilityofnaturalstructureslikewatersheds.Unhealthywatershedscanhaveanega-tiveimpactondrinkingwatersupplies,recreationalopportunities,andthefoodchain,soit’simportanttocomeupwithwaystominimizepollution,erosionandotherthreatstotheworld’sfreshwaterecosystems.

AttheCenterforWatershedStudiesattheVirginiaPolytechnicInstituteandStateUniversity(VirginiaTech),biologicalsystemsengineersareusingageo-graphicinformationsystem(GIS)tohelptheStateofVirginiacorrectthewayitcalculatessedimentvolumeinriversandstreamsinanefforttoreduceerosion.

Upuntilnow,thestatehasdirecteditseffortstowardreducingerosionfromagriculturalandurbanlands,whileignoringanothermajorsourceofsediment–streambankerosion.Duetocomplexityandalackofphysicallybasedalgorithmstodescribetheprocess,thequantificationofstreambankerosionhasbeensignificantlyunderestimated.

ResearchersattheCenterforWatershedStudiesattheVirginiaPolytechnicInstituteandStateUniversity(VirginiaTech)areworkingtoensurethatstreambankerosionisaccuratelycalcu-latedinerosionmodels.

TheengineeringresearchersatVirginiaTechareworkingtodevelopnewmodelsandstatisticalcalcu-lationstomoreaccuratelyestimatesedimentloadingfromstreamchanneldegradation.Thiswillrequirestudyoffluidstructureinteractions,mathemati-calequationsoffluidmechanicsandhydrology,andcomputationalfluiddynamicsmodeling.Theyintendtoincorporatetheirresultsintoalong-termplantohelpensurethatstreambankerosionisaccuratelycalcu-latedintotheerosionmodel.

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ausaid: a Case study in sustainable infrastructure

Thequalityoflifeintheworld’scitiesisdependentonthehealthandsustainabilityofurbaninfrastructure.Toensureinfrastructuresuccess,modernengineersareimplementingtechnologiesthatfallundertheumbrellaof“intelligentinfrastructure.”AccordingtoareportbytheOrganisationforEconomicCo-OperationandDevelopment(OECD),civilandstructuralengi-neerswillbecalledupontoexplore:

• Decisionsupportmodelsandautomationintheelectricitysector,whichcanhelpoptimizegenera-tioncapacity,transmissionlinesandthegrid.Dis-tributionlossescouldbereduced,peakconsump-tionbetterhandled,reliabilityenhancedandtheenvironmentbetterprotected

• Intelligentsystemmodelingtechnologiesinthewatersector,whichcanprovideagreaterabilitytomonitorandcontrolthewatercycleinrealtime.Atthelocalorend-userlevel,thevirtualclosingofthewatercyclecanalsobemonitoredwithsensors,embeddedsoftwareandartificialintelligence

• Integratingmultiplealternativewirelesstechnolo-gies(AWT)intoasinglemulti-serviceplatformintelecommunicationssystems,whichcanleadtoahighlysimplifiedinfrastructureincludingself-healingandself-organizingnetworks.Suchinte-grationcould,forexample,facilitatethecreationofintegratedhealthcaresystems,or“smarthouse”conceptsfortheelderly

• Intelligenthighwaysystemsandadvancedvehicletechnologiesinlandtransportation,whichcouldbringsubstantialbenefitstonetworkmanagement,accidentresponse,driverinformationandroad/railcapacity

Mathematicalmodelswillplayakeyroleinmeetingtheseobjectives.Computationallyunderstandingfun-damentalfactorssuchascarryingcapacity,demo-graphictransition,andrateofnaturalincreasewillbecriticalpiecesnecessarytomeasureprogressandassesswherethegapsare.

TheAustralianAidprogram(AusAID),agovernment-runagency,isusinginfrastructureinvestmentstolifteconomicgrowthandsupportsocialobjectivesinneighboringcountriesinEastAsiaandthePacific,withanexpandingeffortinSouthAsiaandsubSaha-ranAfrica.AusAID’sapproachtoinfrastructureimprovementcentersonfourpillars:

1. Deliveringsustainabletransportinfrastructure

2. Facilitatingincreasedaccesstobasicwaterandsanitationservices

3. Creatingreliableenergyservicesandsupportinginformationandcommunicationtechnologies

4. Supportingurbaninfrastructureplanninganddevelopment

ThroughtheEconomicInfrastructureInitiativeapprovedin2009/10,AusAIDprovidesfundingforhighpriorityinfrastructure,strengtheningthecapacityofpartnergovernments’agenciestorespondtorapidurbanization,andpromotingconditionsforincreasedinfrastructurefinancing.AusAIDisalsoputtinganincreasedfocusonsub-nationalgovernments,inrecognitionofthedecentralizationofinfrastructureplanninganddeliverytakingplacethroughoutthedevelopingworld.

InIndonesia,AusAIDissupportingamajornationalroadsprogram.InPapua,NewGuinea,theorganiza-tionishelpingtoimproveprocessesfortheplanninganddeliveryoftransportinfrastructure.AndintheGreaterMekong,AusAIDislookingtosupportinfra-structureprogramsthatpromoteregionalintegration.

InPapua,NewGuinea,transportinfrastructureimprovementsareessentialfortheefficientflowofproducetomarketsandfortheprovisionofgoodsandservicestoruralandurbancommunities.

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Conclusion

Theextenttowhichtoday’scivilandstructuralengi-neerscanovercomemajordesignandenvironmentalchallengeswillhaveatremendousimpactonhumansocietiesforgenerationstocome.

Designingsustainablestructures,preservingnatu-ralresourcesandmeetingtheinfrastructureneedsofchangingpopulations–allwithinbudgetsaccept-abletogovernmentsandprivatecitizensalike–willrequireextraordinaryeffortandingenuity.

Engineerswillalsocontinuetorelyontechnologicaladvancestohelpthemmeetcurrentandfuturechal-lenges.Enhancedcomputerpoweranddesignsoft-warewillincreaseperformance,andsophisticatedcalculationsoftwarewillhelpensureaccuracyandmitigaterisk.

NOTE:Thetimingofanyproductrelease,includinganyfeaturesorfunctionality,issubjecttochangeatPTC’sdiscretion.

©2012,PTC.Allrightsreserved.Informationdescribedhereinisfurnishedforinformationaluseonly,issubjecttochangewithoutnotice,andshouldnotbecon-struedasaguarantee,commitment,conditionorofferbyPTC.PTC,thePTCLogo,PTCCreoElements/Pro,andallPTCproductnamesandlogosaretrademarksorregisteredtrademarksofPTCand/oritssubsidiariesintheUnitedStatesandinothercountries.Allotherproductorcompanynamesarepropertyoftheirrespectiveowners.Thetimingofanyproductrelease,includinganyfeaturesorfunctionality,issubjecttochangeatPTC’sdiscretion.

J0767-MC-Pushing-Envelope-WP–EN–0912

sources

Arlein,Jacob(2010).“TheShanghaiTower:TheBeginningsofaGreenRevolutioninChina,”CleanTechies,March25,2010.RetrievedMarch2012from:http://www.matternet-work.com/2010/3/shanghai-tower-beginnings-green-revo-lution.cfm

“DevelopingStrategiesforUrbanChannelErosionQuantifi-cationinUplandCoastalZoneStreams,”CenterforWater-shedStudiesatVirginiaTech,2010.RetrievedMarch2012from:http://www.cws.bse.vt.edu/index.php/research/project/developing_strategies_for_urban_channel_ero-sion_quantification_in_upla

Infrastructureto2030:Telecom,LandTransport,WaterandElectricity,OECDPublishing,2006.

“SustainableEconomicDevelopment:InfrastructureThe-maticStrategy,”AusAID,2011.RetrievedMay2012from:http://www.ausaid.gov.au/aidissues/infrastructure/Pages/home.aspx

Winey,Dan(2011).“ShanghaiTower:SustainableStrate-giesinaSuperTallBuilding,”GenslerOnCities,July18,2011.RetrievedMay2012from:http://www.gensleron.com/cit-ies/2011/7/18/shanghai-tower-sustainable-strategies-in-a-super-tall-buildi.html