Pelli Tower in Sevilla: a new concept in the building architecture

PelliTowerinSevilla:Anewconceptinthebuildingarchitecture IgnacioHinojosaSánchez‐Barbudo1;JoséRaulGarridoConejero,BlasMedinaGil,JoséVicenteVicentVelasco ABSTRACT: PelliTowerisbeingbuiltintheCityofSevilla.AnewconceptofbuildingArchitectureisborn. Singularitiesarebeingdescribedinthearticle:structuraltypology,materials,loadsconsideredinthe calculations(seismandwindtunnelTest),andconstructionmethodsusedintheexecution. AlistofthemainquantitiesusedinthePelliTowerisincludedtoemphasizetheimportanceofthe execution. Keywords:Tower,slabs,metallicroof,windtunneltest,seismicstudy 1. INTRODUCTION ThisarticledescribesthemaincharacteristicsofthestructureofthePelliTowerthatwaserectedin theCityofSeville,intheAutonomousCommunityofAndalusia,SouthernSpain. Thisarticledealswiththearchitecturalprojectcurrentlybeingcarriedout,thestructureofwhichnow completelyfinished. Thetextincludesabriefdescriptionoftheprojecttohelpfamiliarisethereaderandalsodetailsthe mainissuesofinterestrelevanttotheprojectofthetower’sstructure. 1AguayEstructuras,S.A.AYESA.Avda.MarieCurie,2ParqueTecnológicodelaCartuja,41092Sevilla,(SPAIN) CorrespondingAuthor;e‐mailaddress(ihinoj[email protected]) 537 Pelli Tower in Sevilla: A new concept in the building architecture Third International Conference on Mechanical Models in Structural Engineering University of Seville. 24-26 june 2015. 2. GENERALDATA ThePelliTowerispartoftheprojectbeingcarriedoutbythe“PuertoTriana”TertiaryServicesCentre, inaplotmeasuringapproximately350x110m2,ontheIslandoftheCartuja,totheWestofthe historiccentreofSeville. Figure1:MapofthecityofSevillawiththeProjectlocation Theprojectissituatedontheoldstreamoftheriver,whichwasmodifiedinaseriesofworksinorder toprotectthecityfromfloods. Figure2:Comparisonbetweenthedifferentstreamsoftheriver 538 Ignacio Hinojosa Sánchez-Barbudo1, José Raul Garrido Conejero, Blas Medina Gil, José Vicente Vicent Velasco In2006theOwnerheldacompetitioninwhichsixinternationallyrenownedteamsofarchitects participated.TheproposalpresentedbythePelliClarkePelliArchitectsStudiowonthecompetition, withthearchitectCésarPelliasprojectleader. Theprojectincludesahigh‐risebuilding,whosegroundflooroccupiesanareaofapproximately1500 m2.Therestofthebuildingworksincludedintheprojectoccupyaround36,000m2ingroundfloor spaceandhaveamaximumheightof3floorsinalimitedarea. Figure3:Generalviewoftheconstruction.Panoramicview. Regardingthestructures,theareaofthefloorslabs(foundationsnotincluded)measures approximately: − Tower:53,000m2. − Rest:152,000m2. Theprojectdealswithatower180maboveground,withfourbasementsthataddaround17m.To date,itisthehighestbuildingtobeerectedinAndalusia. Figure4:LongitudinalsectionofthewholeProject. 539 Pelli Tower in Sevilla: A new concept in the building architecture Third International Conference on Mechanical Models in Structural Engineering University of Seville. 24-26 june 2015. 3. GEOMETRY Theperimeterofeachfloorofthebuildingisovalshaped(twocurvedradii),eachfloorslabatan equidistance(6cm)fromthelowerslab,sothatthebuildingtapersasitsheightincreases. Figure5:Exampleofageometrically. Theverticalelementsthatthefloorslabssupportareacentralinteriorcoreand14perimetral columns: Figure6:Column´sgeometry. 540 Ignacio Hinojosa Sánchez-Barbudo1, José Raul Garrido Conejero, Blas Medina Gil, José Vicente Vicent Velasco Thecolumnsare“dualsloped”inordertoadapttothegeometryofthefaçade: Thetower’sfoundationsaredeep,consistingof4mhighpilecapssupportedbytwoconcentricrings ofscreensmeasuring28mdeep(equivalenttotheheightofaconventionalbuildingofoverten floors)achievingatotalhingedintheresistantmarlstonelayer,typicalofSeville’ssubstratum. Figure7:Tower´sfoundationsdrawing. 541 Pelli Tower in Sevilla: A new concept in the building architecture Third International Conference on Mechanical Models in Structural Engineering University of Seville. 24-26 june 2015. Thetowerwillhaveaslopedroof,solvedwithametallicstructure. Figure8:Slopedroof. 4. STRUCTURALTYPOLOGYANDMATERIALS Thestructuralframeworkdescribedisgoodforthisstructuretype,displayingtwointeresting characteristics: − Interiorcorethatprovidesstrongresistancefromhorizontalwindandseismicforces (importantinthiskindofbuilding),situatedatthesymmetricalcentre. − Laidoutverticalelements(columnsandcore)toavoidimbalancedspanandexcessive inclinationinrelationtotheverticalslope. Themainmaterialusedisreinforcedconcrete.Ametalstructureisemployedintheinteriorslabsof thecoreandintheupperroof. Figure9:Detailoftheinteriorslabs. 542 Ignacio Hinojosa Sánchez-Barbudo1, José Raul Garrido Conejero, Blas Medina Gil, José Vicente Vicent Velasco AtthePreliminaryDesignStageseveralstructuralsolutionswereconsidered.Indeed,fortheslabson core’sexterior,theoptionofametallicstructurewassuggestedandthenruledoutbecauseofthe followingdisadvantagesitimpliedforthisspecificcase: − Needformorethicknessontheslabsinordertoresolvethestructurebecauseofthedifficult designoftherealarchitecturalheightsandthespatialrequirementsforthefacilities; − Thereductionoftheperimeterbecauseoftheslabsduetotheheightandthe“dualsloped” ofthecolumnsmeantthatitwouldbeimpossibletoapplytypedetails,duetothevariability ofthelengthsandtheunionangleswiththecore, Ontheotherhand,someoftheknownadvantagesofreinforcedconcreteare: − Betterbehaviourwhenexposedtofire − Betterbehaviourwhenexposedtoterroristattacks − Itrequireslessmaintenance However,theuseofthismaterialrequiresaheavierstructure.Forthisreason,inorderforthe structureitselftoweighlessandtomaintainthedimensionsofthecolumnstoadesirabledegree, twospecialkindsofconcreteareemployedintheproject: Highresistanceconcrete(RC‐65)inthecolumnsonthelowerfloors,whichallowstogetahigher degreeofresistanceincaseofequalsection; Lightweightaggregateconcrete(LAC‐35)floorslabswhichallowsforareductionofthestructure’s weight,thusreducingthestrainonthecolumns,coreandfoundations. 5. HORIZONTALACTIONS 5.1. Wind Giventhatwearedealingwithahigh‐risebuilding,astudywascarriedoutonwindforces.Toachieve this,windtunneltestswereconductedbytheUniversityofOntario(Canada). Testswerecarriedoutontwomodels: − Towercomplex–surroundings,tothescaleof1:400 − Rooftowerplusfivefloors,tothescaleof1:65 Variedinformationwasobtainedfromthesetests: − Pressuresonthefaçadeandwindloadstoapplytothestructure − Comfortstudyonhigherfloors(maximumacceleration) − Comfortandpedestriansafetystudyinthesurroundings − Windloadsonthemetallicroof Pressurewasmeasuredinatotalof243pointsofwhich110weredistributedinthepodiums(low‐rise buildings). 543 Pelli Tower in Sevilla: A new concept in the building architecture Third International Conference on Mechanical Models in Structural Engineering University of Seville. 24-26 june 2015. Figure10:Windtunneltest. Theentireprojectincludesapedestrianstreetbetweenthelow‐risebuildings(podiums),witha similarconfigurationtothecommercialstreetsinthecentreofSeville.Thisstreet,ofvariablewidth, hassomeofitsendpointslocatedatthebaseofthetower.Thewindtunneltestsallowedfora comfortandpedestriansafetytestofthiszone’suserstotakeplace,basedonwindvelocityandits periodofre‐occurrence. Todoso,velocitymeasuresweretakenat26pointsintotal. Table1.CriteriathatestablishLevelsofComfortandPedestrianSafetybasedontheprobabilityofthe occurrenceofdeterminedwindvelocities(Kapooretal.1990).[1] CRITERIADESCRIPTION AVERAGEVELOCITYEXCEEDED5%OFTHETIME ComfortLevel4Recreation,reading,leisure 4m/s ComfortLevel3Shortrecreationaluse 6m/s ComfortLevel2Walks8m/s ComfortLevel1Transit10m/s CRITERIADESCRIPTION AVERAGEVELOCITYEXCEEDEDONCEAYEAR SafetyLevel2 SafetyLevel1 Safeallthetime Safeonlyingoodweather 15m/s 20m/s Theresultsweresatisfactoryanddidnotinvolvetheneedtochangetheinitialarchitecturaldesigns. 544 Ignacio Hinojosa Sánchez-Barbudo1, José Raul Garrido Conejero, Blas Medina Gil, José Vicente Vicent Velasco Theaccelerationexperiencedbyusersofthetower,asaconsequenceofwindforces,wasalso studied.Thefindingsindicatethathighestacceleration,7.8thousandthofgravity,occurredatthe pointscorrespondingtothesemi‐majoraxisofthehigherfloors.Thismaximumacceleration,below 10thousandthofgravity,withareturnperiodoftenyears,isbelowtheusuallimitsappliedtothis kindofbuilding,evenforresidentialuse: Figure11:Variouswin d ‐inducedAccelerationCriteria(J.Kilpatrick). Specialattentionwasalsopaidtothewindactionontheroofofthetower,beinganopen,lightweight structure,situatedinthehighestpartofthebuilding. Pressureswereappliedtomorethan170pointsofthehigher,lower,risingetc.areas.Theestimation oftheforcesandmomentswasmadebasedontheintegrationofthetemporaryseriesoflocalforces ineachoneofthetributaryareasinwhichtheseareasaredivided.Basedontheobtainedresults,the mostunfavorableloadsareestimatedtobe(maximumandminimumpeakvalues): − Totalmomentsaroundsixaxes,threeineachdirection − Supportloads(vertical)anddragging(horizontal)moreunfavorable 545 Pelli Tower in Sevilla: A new concept in the building architecture Third International Conference on Mechanical Models in Structural Engineering University of Seville. 24-26 june 2015. Ontheotherhand,toguaranteecompleteconcrete‐ steelbehaviourinthecolumnsofthemixed section,wieldedconnectorswereemployedinthewingsoftheprofiles. 7.3. Geotechnicalcampaign Forthecorrectsimulationofthepropertiesoftheterrain,awide‐reaching,geotechnicalcampaign wascarriedout,includingsurveysthatreachedaround60mdeep. Specialstudieswereperformed,suchasseismicstudiesofsurfacewavesthroughpassiveandactive waves,thatallowedfortheconfirmationofthemodulevaluesofdynamicdeformationforthe calculationofthefoundationsexposedtotheactionofhorizontalweights. Figure18:Resultsoftheseismicstudywithsuperficialwaves 552 7.4. Behaviourwhenexposedtoterroristacts TheOwnerconsidereditpertinenttoperformaglobalstudyonterroristattacks.Thestudywas carriedoutbyaBritishEngineerspecialisinginthefield,whoinhisinvestigationsincludedananalysis ofthepossibleconsequencesoftheimpactofanaeroplanecomingintocontactwiththetower. Inthispartofthestudy,calculationsweremadebymeansofsimulation,usingcomputerisedmodels toobtainconclusionsonthebehaviourofthestructureuponimpactwithanaeroplaneinseveral possibleconfigurations. Forsecurityreasons,imagesofthesestudiesarenotshownbutitmaybesaidthattheresultswere satisfactory,makingitclearthattheemploymentofreinforcedconcretecolumnsoverawidesection, alsoprovideadvantagesfromthispointofview. 8. SOMECOMMENTSONTHEEXECUTION Thepilecapwasencasedinconcreteinsixstages,withsomepointsreceivingreinforcementofeight layersofɸ32mmbars: Figure19: Stagesofpilecapexcetion. Thecorewasconstructedusingself‐climbingformworkontheinteriorface,compatiblewiththe project’sdesignfortheinteriorfloorslab‐ coreunion,thatwasdefinedasrigid,followingthe conventionalframeworkintheorderofexecution:wall‐slab‐wall. 553 Pelli Tower in Sevilla: A new concept in the building architecture Third International Conference on Mechanical Models in Structural Engineering University of Seville. 24-26 june 2015. Figure20:Self‐climbingformworkusedinthecoreexecution. Theclimbingformworksystememployedintheworksforthefloorslabsconsistedofreusabletables withadjustablelegs.Acompatibilitystudyofthestrippingtimes,evolutionofresistanceintime,and workandprojectloads,wascarriedoutpriortotheiruse. Figure21:Reusabletableswithadjustablelegs. 554 Ignacio Hinojosa Sánchez-Barbudo1, José Raul Garrido Conejero, Blas Medina Gil, José Vicente Vicent Velasco Anotheraspectoftheprojectthatalsoreceivedspecialattention,bothduringtheProjectand executionstages,wasthereinforcementofthelintelsondoorgapsinthecore,beingheavily reinforcedareasasaresultoftheconcentrationofforcesmostlycausedbyhorizontalactions. Figure22:Reinforcementofthelintelsondoorgapsinthecore. Themetallicroofconsistsonalighttriangularcover,definedwithaballandrodsystemworkingat axialtowcompression.Thisrooftowerincludesaseriesofmetallicovalslats,inkeepingwiththeslats ofthefaçadeofthelastcompletefloorofthebuilding. 555 Pelli Tower in Sevilla: A new concept in the building architecture Third International Conference on Mechanical Models in Structural Engineering University of Seville. 24-26 june 2015. Figure23:Metallicovalslatsusedintherooftower 556 9. QUANTITIES Someofthequantitiesusedintheprojectaredetailedbelow: •Areaofslabfoundations: 1,537.05m2 •Volumeofconcrete: 5,822.57m2 •Weightofpassivesteelreinforcement(kg): 1,383,681.41Kg •Unitweightofshearcolumns: 496,38Kg(425columns) •Groundfloordimensionsofthecolumns: 1.5mx1.5m •Slabcementtype: CEMIV/B(V)32.5N •Slabadditivetype: Superplasticiser •Screencementtype: CEM‐II/A‐M42.5R •Slabadditivetype: Superplasticiser •Concretingphases: Two2mdeeplayers Threefractionsperlayer62.5m3/hour Providedbytwofloors Table2.CharacteristicsandspecificationstableEHE CHARACTERISTICS AND SPECIFICATIONSTABLEEHE STRUCTURALELEMENT LOCALISATION PILECAP SCREENS REINFORCEDCONCRETE (Art.30) CLASSIFICATION(Art.39.2) HA‐35/B20/IIa HA‐30/F/20/IIa+Qa COATING(MIN,+MARG)(Art.37) 45+5=50mm 70+5=75mm COEF,PARC,Seg(ELU)(Art.15.3) 1.50 1.50 CONTROLOFCONCRETE(Art88.4) STATISTIC STATISTIC REINFORCINGOFSTEEL (Art.31) DESIGNATION(Art.31.2) B500SD B500SD COEF,PARC,Seg(ELU)(Art.15.3) 1.15 1.15 CONTROLOFOFSTEELNORMALLEVELNORMALLEVEL 557 Pelli To w Third In t Universi t PICTURE ( w er in Sevill a t ernational C t y of Seville. ( S) a : A new co n onference o 24-26 june 2 cept in the b n Mechanic a 2 015. b uilding arch i a l Models in S PROJ Type Stor e Fram Cons t PROJ CLIE N ARC H STRU ‐ ‐ B M&E MAI N Proje Wor k i tecture S tructural E n ECTDESCRIP T /occupancy: ys/height:38 eCost:23.3 8 t ructionperi o ECTTEAM N T:CaixaBank H ITECT:Pelli, C CTURALENGI BasicProj Technical B asicproject: ENGINEER:A N CONTRACT O ctManager: A k sandconstr u n gineering T ION Offices storeys(180, 8.824,02eur o d:2007–20 1 C larke,PelliA r NEER e ctandCons t consultantin FhecorIngeni y esa O R:UTEFCC‐I A ynova u ctionsupervi , 50m) o s 1 2 r chitects&A Y t ructionproj e ConceptDes i eros,Consul t NABENSA sion:AYESA Y ESA e ct:Ayesa i gnand ores. 558 Ig n REFERE N [1] W C [2] A A [3] [4] [5] [6] “ C [7] “ ( [8] “ n acio Hinojo s N CES KAPOOR,V. W INDSTUD C ONGRESS A A RIZA,P.A N A NSYS”.PU B EUROCODE ECCSNº22, EHE‐08.INS T DEESPAÑA. “ PROYECTO C IENTÍFICO‐ “ MONOGR Á (CTBA)EN M “ CONSTRU C EJECUCIÓN ” s a Sánchez - ,PAGE,C., S IESTOAID T A BSTRACTS, N DSÁEZ,A. B LICACIONE 3. “DESIGN O 1.976.“MA T RUCCIÓN D  DEEDIFICI O TÉCNICADE Á FICODEDIC M ADRID”.R E C CIÓNYCO N ” . Barbudo1, J o S TEFANOWI C T HEPLANNI N AMERICAN 1 .999,“MÉ T SDELAUNI V O FSTEELST N UALONS T D EHORMIG Ó O SALTOS”. W LHORMIG Ó A DOALCO N E VISTAHOR M N TROLDEE D o sé Raul Ga STR U Stabi l (32.0 0 Foun d diap h Colu m diam e Core: conc r Floor dept h OTH E The P Sevill issit u Expo s com p built ‐ C Z,P.,LIVES E N GOFAM A SOCIETYO F T ODODELO S VERSIDAD D RUCTURES” . T ABILITYOF Ó NESTRUC T W ORKGRO U Ó NESTRUCT U N JUNTOUR B M IGÓNYA C D IFICIOSALT O rrido Conej e CTURALSOL U l itysystem:E l 0 x16.00) d ation:Deep h ragmconcre t m ns:Sloping c e ter.HA‐65t o Thicknessb e r etegradeH A slabs:Light w h andmaxim u E RINFORMA T P elliToweris a e,builtunde r u atedinLaCa s itionof1992 p risesover20 0 upareaof11 E Y,F.,ISYU M A JORDEVEL O F CIVILENGI N S ELEMENT O D ESEVILLA. M . 1.993. STEELSTRU C T URAL.MINI U P1/5.MO N U RAL.ACHE . B ANOCUAT R C ERO.Nº24 9 O S”,WORK e ro, Blas Me d U TION lipticalreinfo f oundation w t ewalls. c ompositecol o HA‐30. tween0.70a n ‐40. w eightconcre t u mspanof9. 6 T ION a nofficeskys c themasterpl rtuja,former (Expo’92).T h 0 .000m2ofsi 0m*350m. M OV,N,“PE D O PMENT”,S T N EERS,1.99 0 O SFINITOS. I M ANUALES U C TURES”. S TERIODE F N OGRAFÍA2 0 .  R OTORRES B 9 .JULY‐SEP T GROUP3/6 , d ina Gil, Jos é Vicen t o rcedconcret e w ithtworings umnswith1. 2 nd0.40man d t eslabwith3 6 0m. c raperinthe s l anofPuerto zoneofthe U h ewholecon s i ngularstruct u DESTRIANL E T RUCTURES 0 . I NTRODUC C UNIVERSIT A F OMENTO. G 0 /21.ASOCI BUSSINESS A T EMBER2.0 0 , “COMISIÓ N é Vicente t Velasco e core of 2 –1.0 d  50mm s outhof T riana.It U niversial s truction u reinan E VEL IÓNA A RIOS. G OBIERNO ACIÓN A REA 0 8. N 3. 559