15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some...
Transcript of 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some...
![Page 1: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/1.jpg)
DesigningWoodFrameStructuresForHighWinds
![Page 2: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/2.jpg)
“TheWoodProductsCouncil”isaRegisteredProviderwithTheAmericanInstituteofArchitectsContinuingEducationSystems(AIA/CES),Provider#G516.
Credit(s)earnedoncompletionofthiscoursewillbereportedtoAIACESforAIAmembers.CertificatesofCompletionforbothAIAmembersandnon-AIAmembersareavailableuponrequest.
ThiscourseisregisteredwithAIACESforcontinuingprofessionaleducation.Assuch,itdoesnotincludecontentthatmaybedeemedorconstruedtobeanapprovalorendorsementbytheAIAofanymaterialofconstructionoranymethodormannerofhandling,using,distributing,ordealinginanymaterialorproduct.________________________________Questionsrelatedtospecificmaterials,methods,andserviceswillbeaddressedattheconclusionofthispresentation.
![Page 3: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/3.jpg)
CourseDescription
Woodframingisconducivetomeetingthechallengesofwind-resistivedesign.Amongitscharacteristics,woodcancarrysubstantiallygreatermaximumloadsforshortdurationsoftimeasisthecaseinhigh-windevents.Woodbuildingsalsotendtoincludemultipleandoftenredundantloadpathsforresistancetowindforces.Thispresentationwillcoverthedesignofabuilding’swind-resistingsystem,includingwindloadcalculations,diaphragms,shearwallsandcollectors.Loadpathcontinuitywillbediscussed,aswilluniquedesignconsiderationsfordesigningwood-framestructurestoresistuplift,in-plane,andout-of-planewindloads.Designexampleswillbepresentedtoillustraterelevantdesignproceduresanddetailingbestpractices.
![Page 4: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/4.jpg)
LearningObjectives
1. ReviewtheparametersforbuildingwindloadcalculationsperASCE7andtheInternationalBuildingCode.
2. Examinethethreemaintypesofbuildingwindloads(uplift,in-plane,andout-of-plane)anddesignconsiderationsassociatedwitheach.
3. Discusscommonwood-frameshearwall,diaphragm,andtie-downsystems.
4. Recognizethebenefitsofredundancyinwind-resistingwood-framesystems.
![Page 5: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/5.jpg)
Overview
• Wind• CalculatingWindLoads• Uplift• WallDesign• Diaphragms• Shearwalls
![Page 6: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/6.jpg)
MakingourBuildingsSafe- WindHighwindloadsactingonabuildingarearesultofavarietyoftypesofwindstormswhichhavedifferingnaturesandoccurrences.Buildingdesignshouldincludewindloadresistanceandaccountforthecharacteristicsofthetypeofstormsthatcanimpactthebuilding.
![Page 7: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/7.jpg)
MakingourBuildingsSafe- Hurricanes
ImageSource:WholeBuildingDesignGuide
![Page 8: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/8.jpg)
ImageSource:WholeBuildingDesignGuide
MakingourBuildingsSafe- Tornadoes
![Page 9: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/9.jpg)
“Experiencehasshownthatcode-compliantwoodbuildingsperformexceedinglywellduringhighwindeventssuchashurricanes.Woodisstrongandmostwood-framebuildingsoffertheadvantageofrepetitivemembersandmultipleconnections,whichtogethercreateredundantloadpathstoeffectivelytransferwindforcesfromthebuildingenvelopetothefoundationandsoilbelow”.
UsingWoodtoResistWind:Benefits
QuoteSource:Wind-ResistiveDesignofWoodBuildings,AWC
Photo:NewGenesisApartments,Killefer Flammang Architects,KCKim,GBConstruction
![Page 10: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/10.jpg)
WhyWood?
UsingWoodHelpsReduceYourEnvironmentalImpact
WoodProductsPlayaSignificantRoleinModernEconomy
WoodCostsLess
WoodisVersatile
WoodMeetsCode
WoodisDurable
WoodisRenewable
![Page 11: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/11.jpg)
WindLoadsWindloadsactingonbuildingsaremodeledasuniformsurfaceloads.Windloadscancreatebothpositiveandnegativeloads(inwardsandoutwardsloads)onbuildingsurfacesandcreatethreedifferentloadingconditions:
• Uplift
• Racking/overturning
• Sliding/shear
![Page 12: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/12.jpg)
WindForceDistribution
ImageSource:WholeBuildingDesignGuide
![Page 13: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/13.jpg)
WindLoadDemand
IBC:BaseCode– ReferencesASCE7fordeterminationofwindforcesonstructures
ASCE7:ReferencedStandard.Providesinformationrequiredtodeterminewindforcesona
structure
![Page 14: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/14.jpg)
CalculatingWindLoads
• ASCE7-05§ Chpt.6:ContainedAllProvisions
• ASCE7-10§ Chpt.26:GeneralRequirements§ Chpt.27:MWFRS– Directional§ Chpt.28:MWFRS– Enveloped§ Chpt.29:OtherStructures§ Chpt.30:Components&Cladding§ Appendices
![Page 15: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/15.jpg)
DetermineBasicWindSpeed,Vmph
PerASCE7-10Fig.26.5-1A
115
![Page 16: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/16.jpg)
DetermineBasicWindSpeed,V
• ASCE7-05§ ASDLoads§ 90mphperfig.6-1
• ASCE7-10 (figuresincorporateimportancefactor)§ UltimateLoads§ 115mphperfigure26.5-1AforRKII
§ 120mphperfigure26.5-1BforRKIII&IV
§ 105mphperfigure26.5-1CforRKI
Note:RK=RiskCategoryImageSource:SKGhosh Associates
![Page 17: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/17.jpg)
WindSpeedByLocationSoftware
windspeed.atcouncil.org
![Page 18: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/18.jpg)
RunningtheNumbers:VelocityPressure
• qz =0.00256KzKztKdV2
§ qz =velocitypressure(psf)§ Kz – Exposurecoefficient,Table30.3-1(7-05Table6-3)
§ Kzt – Topographicfactor,Figure26.8-1(7-05Figure6-4)
§ Kd – Directionalityfactor,Table26.6-1(7-05Table6-4)
![Page 19: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/19.jpg)
WindLoadsTypes
2TypesofWindLoads
• MWFRS– MainWindForceResistingSystemAnassemblageofstructuralelementsassignedtoprovidesupportandstabilityfortheoverallstructure.Thesystemgenerallyreceiveswindloadingfrommorethanonesurface.Eg.Shearwalls,diaphragms
• C&C– Components&CladdingElementsofthebuildingenvelopethatdonotqualifyaspartoftheMWFRS.Eg.Wallstuds
![Page 20: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/20.jpg)
MWFRSMethodOptions
TwoMethodsofCalculatingMWFRSloads:• Envelope:Pressurecoefficientsrepresent“pseudo”loadingthatenvelopethedesired
moment,shear...Limitedtolow-rise
• Directional:Pressurecoefficientsreflectwindloadingoneachsurfaceasafunctionofwind
direction
![Page 21: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/21.jpg)
MWFRSMethodOptions
Howtodecidewhichmethodtouse:Envelope:ASCE7-10Chapter28• Part1:Canbeusedforallregular-shapedenclosed&partiallyenclosedbuildingswithmeanroofheight≤60ft
• Part2(Simplified):Canbeusedforallregular-shaped,enclosed,simplediaphragmbuildingswithmeanroofheight≤60ft
![Page 22: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/22.jpg)
MWFRSMethodOptions
Howtodecidewhichmethodtouse:Directional:ASCE7-10Chapter27• Part1:Canbeusedforallregular-shapedbuildings
• Part2(Simplified):Canbeusedforallregular-shaped,enclosed,simplediaphragmbuildingswithmeanroofheight≤160ft
![Page 23: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/23.jpg)
MWFRSMethodOptions
ASCE7-10MWFRSOptions
Part1:Enclosed,PartiallyEnclosed,Open
BuildingsAllHeights
DirectionalMethod,CH27 EnvelopeMethodCH28
Part2:Enclosed,Simple
DiaphragmBuildingswithh≤160ft
Part1:Enclosed&PartiallyEnclosed Buildingswithh≤60ft
Part2:Enclosed,Simple
DiaphragmBuildingswithh≤60ft
Note:WindTunnelProcedure(ASCE7-10Chpt31)canalsobeused
Simplified,Directio
nal
Simplified,Envelope
![Page 24: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/24.jpg)
SimpleDiaphragmBuildings
Abuildinginwhichbothwindwardandleewardwindloadsaretransmittedbyroofandverticallyspanningwallassemblies,throughcontinuousfloorandroofdiaphragms,totheMWFRS.
SimpleDiaphragmBuilding Non-SimpleDiaphragmBuilding
![Page 25: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/25.jpg)
Example:FlatRoof,30’x60’Building:
Ch.27Directional
• WindwardWall(0.8)• LeewardWalls(-0.3)
• DetermineGustEffect(G)=0.85
• ForMWFRSGCpf =(1.1)(0.85)=0.935
Ch.28Enveloped
§ LimitedtoLow-Rise(h≤60’)§ WindwardWall(0.4)
§ LeewardWall(-0.29)
§ ForMWFRSGCpf =0.69
35%differenceinloadingnotaccountingforendzones.
ComparisonofmethodstocalculateMWFRS(GCpf)
ASCE7-10Figure28.4-1
ASCE7-10Figure27.4-1
![Page 26: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/26.jpg)
MWFRSMethodOptions
Beneficialtousetheenvelopemethodwhenitslimitationsaremet
ASCE7-10Fig.C28.4-1
![Page 27: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/27.jpg)
MinimumWindLoads
ForboththeDirectional&EnvelopeMethods,considerminimumwindloads:ASCE7-10Sections27.1.5&28.4.4:
WindLoadsforMWFRSinanenclosedorpartiallyenclosedbuildingshallnotbelessthan:§ 16psf (ultimateor~10psf ASD)forwalls§ 8psf (ultimateor~5psf ASD)forroofs
Wallandroofloadsshallbeappliedsimultaneously.Thedesignwindforceforopenbuildingsshallbenotlessthan16psf ultimate(openbuildingprovisionsapplyonlytoDirectionalMethod).
![Page 28: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/28.jpg)
BuildingEnclosure
Accountsfordegreetowhichwindforcescanenterandexitastructure,creatingvaryingamountsofinternalwindpressure
3buildingenclosureclassifications:Open,PartiallyEnclosed,andEnclosed
![Page 29: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/29.jpg)
RunningtheNumbers:DesignWindPressure
• p=qh[(GCp)– (GCpi)]§ p=Designwindpressure(psf)§ qh =velocitypressure(psf)§ GCp:Externalpressurecoefficient
Figures27.4-1,28.4-1,30.4-1Note:Figure27.4-1alsorequiresGusteffectfactor(G)persection26.9
§ GCpi:Internalpressurecoefficient,Table26.11-1(7-05Figure6-5)
![Page 30: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/30.jpg)
InternalPressureCoefficient– Table26.11-1
+/- 0.18- Enclosed+/- 0.55– PartiallyEnclosed
![Page 31: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/31.jpg)
ActualWindLoads
ComparingASCE7-05toASCE7-10:LoadCombinations:
7.0.6D+W(ASCE7-05)7.0.6D+0.6W(ASCE7-10)
3SecondWindSpeed:90mph (ASCE7-05)115mph*√0.6=89mph(ASCE7-10)
Finalloadonbuildingisverysimilar
![Page 32: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/32.jpg)
IBC’sAlternateAll-HeightsMethodIBCSection1609.6providesanalternativetotheDirectionalWindLoadProcedureinASCE7
AlternateAll-HeightsMethod
Limitationssuchas:• BuildingHeight≤75ft• BuildingHeight/Width≤4• Buildinghassimplediaphragm• Others(IBC1609.6.1)
Pnet =0.00256V2KzCnetKzt
![Page 33: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/33.jpg)
IBC’sAlternateAll-HeightsMethod
Pnet =0.00256V2KzCnetKzt
• V=Basicwindspeed(ASCE7)
• Kz =Exposurecoefficient(ASCE7)
• Kzt =Topographicfactor(ASCE7)
• Cnet =Net-pressurecoefficient(IBCTable1609.6.2)
![Page 34: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/34.jpg)
IBC’sAlternateAll-HeightsMethod
IBCTable1609.6.2
![Page 35: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/35.jpg)
WindBorneDebrisRegions
PerASCE7-10,section26.2,WindBorneDebrisregionsareAreaswithinhurricane-proneregionswhereimpactprotectionisrequiredforglazedopenings(buildingsinRiskCategoryIareexempt– ASCE26.10.3&IBC1609.1.2)
Protectionofglazedopeningsisrequired(ASCE726.10.3):
• Within1mileofthecoastalmeanhighwaterlinewherethebasicwindspeedisequaltoorgreaterthan130mph,or
• Inareaswherethebasicwindspeedisequaltoorgreaterthan140mph
• Otherexemptions,testingrequirementsgiveninASCE7-10,section26.10.3
![Page 36: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/36.jpg)
WindBorneDebrisRegions
Image:greenheck.com
![Page 37: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/37.jpg)
WindBorneDebrisRegions
Failedopeningscanchangeastructurefromenclosedtopartiallyenclosed,significantlyincreasingwindforces
![Page 38: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/38.jpg)
Let’sTalkAboutWood
1.Uplift– LoadPathContinuity2.Wall– StudDesign3.Diaphragms4.Shearwalls
![Page 39: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/39.jpg)
UpliftWindLoads
Uplift– Outward(suction)forceactingonroof
Loadpath- rooftofoundationrequiredunlessdeadloadisgreaterthanuplift
![Page 40: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/40.jpg)
UpliftLoads
Source:strongtie.com
![Page 41: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/41.jpg)
MethodstoResistUpliftLoads
• Mechanicalconnectors(straps,hurricaneties,screws,threadedrods)
• Sheathing
• DeadLoads
Source:strongtie.com
![Page 42: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/42.jpg)
UpliftResistance:MechanicalConnectors
Source:IIBHS
![Page 43: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/43.jpg)
UpliftResistance:WallSheathing
• Whenjoints,fastenersareconsidered,canusesheathingtoresistuplift
• SDPWSSection4.4
SDPWSFigure4I
![Page 44: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/44.jpg)
UpliftResistance:DirectLoadPath
Importanttodetailupliftrestraintconnectorstoprovidedirectloadpath
![Page 45: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/45.jpg)
RoofGeometry&Uplift
ImageSource:WholeBuildingDesignGuide
![Page 46: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/46.jpg)
Uplift:MWFRSorC&C?
ConsidermemberpartofMWFRSif:• TributaryArea>700ft2 perASCE7-1030.2.3• LoadcomingfrommorethanonesurfaceperASCE7-1026.2
![Page 47: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/47.jpg)
Uplift:MWFRSorC&C?
AWC’sWFCMcommentaryC1.1.2statesthatMWFRSisusedforallupliftconditions:
TherationaleforusingMWFRSloadsforcomputingtheupliftofroofassembliesrecognizesthatthespatialandtemporalpressurefluctuationsthatcausethehighercoefficientsforcomponentsandcladdingareeffectivelyaveragedbywindeffectsondifferentroofsurfaces.
![Page 48: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/48.jpg)
Uplift:MWFRSorC&C?
ASCE7-1026.2commentaryprovidessomediscussiononuplift&MWFRSvs.C&C.
ComponentsreceivewindloadsdirectlyorfromcladdingandtransfertheloadtotheMWFRS.Examplesofcomponentsincludefasteners,purlins,girts,studs,roofdecking,androoftrusses.ComponentscanbepartoftheMWFRSwhentheyactasshearwallsorroofdiaphragms,buttheymayalsobeloadedasindividualcomponents.
![Page 49: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/49.jpg)
EffectiveWindArea
Forwinddesign,tributaryareadoesnotnecessarily=effectivewindarea
EffectiveWindArea(EWA)- Twocases:• Areaofbuildingsurfacecontributingtoforcebeing
considered(tributaryarea)• Longandnarrowarea(wallstuds,rooftrusses):width
ofeffectiveareamaybetakenas1/3length;increaseseffectivearea,decreasesload(perASCE7-10section26.2commentary);EWA=L2/3
![Page 50: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/50.jpg)
EffectiveWindAreaExample
44’-0”
Trusses@2’o.c.
44’-0”
Trusses@2’o.c.
Trib.A=(44)(2)=88ft2 EWA=442/3=645ft2
![Page 51: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/51.jpg)
UpliftExampleCalculation
• RoofFramingRafter• 20’Span• 2’Spacing• 2’Overhang• 115mphExposureB• RoofH=80ft• 65’x220’
Photocredit:MattTodd&PBArchitects
![Page 52: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/52.jpg)
MWFRS- ExternalPressureCoefficient
Lookatwindactingonbuilding’slongside:L=65ft,h/L=80/65=1.23Cp =1.3,-0.18
ASCE7-10Fig.27.4-1
![Page 53: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/53.jpg)
• GCp:(0.85)(-1.3)=1.105(26.9.4&Fig.27.4-1)• GCpi:±0.18(Table26.11-1)• qh =0.00256KzKztKdV2
§ Kz :0.93– Table27.3-1§ Kzt :1.00- Figure26.8-1§ Kd :0.85- Table26.6-1§ Vu:115mph
• qh =26.8psf• p=(26.8psf)(-1.105+(-0.18))=34.4psf
MWFRS- Runningthenumbers
![Page 54: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/54.jpg)
MWFRS- RoofOverhangpersection27.4.4• ForOverhangs:ASCE727.4.4– useCp =0.8onundersideofoverhang,usesametoppressurescalculatedfortyp.roof
• poh =(26.8psf)(-0.8)(0.85)=18.2psf• pext =(26.8psf)(-1.105)=29.6psf• poh net=18.2+29.6=47.8psf
Poh
pext
PerASCE7-10section27.4.4
pint
![Page 55: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/55.jpg)
MWRFS- DeterminingtheUpliftLoad• p=(34.4psf)(2ft)=68.8plf• poh =(47.8psf)(2ft)=95.6plf
68.8plf
Uplift=0.6(95.6plf(2ft.)+68.8plf*20ft/2)=528lbsDeadLoad=0.6((2+20/2)*10psf*2ft)=144lbsNetUpliftatLeftSupport=528lbs -144lbs =384lbsNote: Itiscommonpracticetouse2sets ofdead loads:highestpotential dead loadsforgravity,lowestpotential deadloadsforuplift
95.6plf
![Page 56: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/56.jpg)
C&C- ExternalPressureCoefficient3zoneswithdifferingwindloads:
1:Field2:Perimeter3:Salientcorners
a=smallerof10%ofleasthorizontaldimensionor0.4h,butnotlessthaneither4%ofleasthorizontaldimensionof3ft
ASCE7-10Fig.30.4-2A
![Page 57: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/57.jpg)
C&C- ExternalPressureCoefficient– Fig.30.4-2A
EWA=H2/3=222/3=161ft2
GCP =-1.1FORINTERIOR
ASCE7-10Fig.30.4-2A
![Page 58: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/58.jpg)
• GCp:-1.1(Figure30.4-2A)• GCpi:±0.18(Table26.11-1)• qh =0.00256KzKztKdV2
§ Kz :0.93- Table30.3-1§ Kzt :1.00- Figure26.8-1§ Kd :0.85- Table26.6-1§ Vu:115mph
• qh =26.8psf• p=(26.8psf)(-1.1+(-0.18))=34.3psf
C&C- Runningthenumbers– Zone2
![Page 59: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/59.jpg)
C&C- RoofOverhangpersection30.10• ForOverhangsFigures30.4-2A&30.10-1areutilized• poh =26.8psf(1.7+0.18)=50.4psf• ps =pw =34.3psf• poh net=50.4+34.3=84.7psf
ps
pW
pOH
EWA=2*2=4sf
GCp =-1.7
PerASCE7-10Fig.30.10-1ASCE7-10Fig.30.4-2A
![Page 60: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/60.jpg)
C&C- DeterminingtheUpliftLoad• p=(34.3psf)(2ft)=68.6plf• poh =(84.7psf)(2ft)=169.4plf
68.6plf
Uplift=0.6(169.4plf(2ft.)+68.6plf*20ft/2)=615lbsDeadLoad=0.6((2+20/2)*10psf*2ft)=144lbsNetUpliftatLeftSupport=615lbs -144lbs =471lbsNote: Itiscommonpracticetouse2sets ofdead loads:highestpotential dead loadsforgravity,lowestpotential deadloadsforuplift
169.4plf
![Page 62: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/62.jpg)
Overview
• Wind• CalculatingWindLoads• Uplift• WallDesign• Diaphragms• Shearwalls
![Page 63: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/63.jpg)
DesigningWoodWalls
![Page 64: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/64.jpg)
WindLoadsUniformsurfacewindloadsgenerallyincreasewithbuildingheight
ASCE7-10Fig.27-6.1
Ifwindloadsvarywithbuildingheight,commontousehigherwindloadoverasinglestoryorbuilding
![Page 65: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/65.jpg)
Panels
Hinges
L/dRatio
Unbraced Length
WallVeneer
WindonlyloadingC&C
DesignProperties
WallDesignConsiderations
![Page 66: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/66.jpg)
LoadsintoWSPWindloadsaretransferredtowallframingstudsthroughwoodstructuralpanels(sheathing)
SDPWSTable3.2.1
ForASDCapacity:DivideNominalCapacityby1.6
ForLRFDCapacity:MultiplyNominalCapacityby0.85
![Page 67: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/67.jpg)
TOPPLATE
L/D<502x6:22’-11”2x4:14’-7”
Whichwallisgoingtowithstandhighwinds?
![Page 68: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/68.jpg)
GableEndWallHinge
![Page 69: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/69.jpg)
GableEndBracingDetails• AWC’sWoodFrameConstructionManual
![Page 70: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/70.jpg)
GableEndBracingDetails
• Gableendwallandroofframingmayrequirecrossbracing
![Page 71: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/71.jpg)
FullHeightStudsatGableEndWalls
• Ifnoopeningsingableendwallexist,candesignstudstospanfromfloor/foundationtoroof(varyingstudheights).Mayrequirecloserstudspacings attallerportionsofwall
![Page 72: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/72.jpg)
GableEndWallswithOpenings
![Page 73: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/73.jpg)
GableEndWallswithOpenings
![Page 74: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/74.jpg)
GableEndWallGirts&Jambs
• Oftengableendwallsarelocations oflargewindows
• Horizontallyspanningmember inplaneofwallbreaksstud length,providesallowableopening
Verticallyspanningjambs
Horizontallyspanning
girts
![Page 75: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/75.jpg)
DeterminingUnbraced Length
Whatistheunbracedlength,lu ?Strong&weakaxis
![Page 76: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/76.jpg)
Gypsum&WeakAxisBuckling
NDSCommentary:“Experiencehasshownthatanycodeallowedthicknessofgypsumboard,hardwoodplywood,orotherinteriorfinishadequatelyfasteneddirectlytostudswillprovideadequatelateralsupportofthestudacrossitsthicknessirrespectiveofthetypeorthicknessofexteriorsheathingand/orfinishused.”
![Page 77: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/77.jpg)
IntermediateWallStudBlocking
![Page 78: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/78.jpg)
CalculatingDeflection– IBCTable1604.3
ForΔ ofmostbrittlefinishesusel/240
ForC&Cpressuresa30%loadreductionisallowedforΔ only(IBCTable1604.3footnotef)
f.Thewindload ispermitted tobetakenas0.42times the"component andcladding” loadsforthepurposeofdetermining deflection limits herein.
![Page 79: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/79.jpg)
WoodStudswithBrickVeneer- Deflection
IBCTable1604.3:min.walldeflectionwithbrittlefinishes=L/240
BrickIndustryAssociationrecommendsmuchstricterlimits
StructureMagazineMay2008article,HaroldSprague
BIATechNote28
![Page 80: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/80.jpg)
Example:LargeDiamondRetailer22’tallwoodframedwalls.
Assumestuds16”o.c.
130mphExposureB
LeastHorizontalDim.=64ft.
![Page 81: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/81.jpg)
ExternalPressureCoefficients– WallZones4&5
a=Lesserof:
• 10%leasthorizontaldimension(LHD)64’*0.1=6.4’
• 0.4h=0.4*22=8.8’.Butnotlessthan:
• 0.04LHD=2.6’or3’
Usea=6.4’forzone5
![Page 82: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/82.jpg)
ExternalPressureCoefficients- Walls
Assumewallstudsare22’long
EWA=h2/3=161ft2
Zone4:
GCpf =-0.89
GCpi =-0.18(Table26.11-1)
Zone5:
GCpf=-1.0
ASCE7-10Figure30.4-1
![Page 83: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/83.jpg)
Runningthenumbers– Zone4
• GCpf:0.89(Figure30.4-1)• GCpi:0.18(Table26.11-1)• qh =0.00256KzKztKdV2
§ Kh :0.70- Table30.3-1§ Kzt :1.00- Figure26.8-1§ Kd :0.85- Table26.6-1§ V:130mph
• qh =25.74psf• p=25.74psf(0.89+0.18)=27.54psf• 0.6W=0.6(27.54)=16.52psf
![Page 84: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/84.jpg)
LumberDesignProperties
DesignPropertiesfromNDSSupplement.
Assume2x8DouglasFir-Larch#2Studs,16”o.c.
RepetitiveMemberadjustment=1.25
SizeFactor=1.2
DurationofLoad=1.6
![Page 85: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/85.jpg)
StudRepetitiveMemberFactorNoteonstudrepetitivememberfactor:
NDSsection4.3.9:CR =1.15
SDPWSTable3.1.1.1largerCR factorsforstudsinbending,16”spacingmaxincreasedto24”in2015SDPWS),interiorcoveredwithmin.½”gypsum,exteriorcoveredwithmin.3/8”WSP,otherfastenerrequirements
DESIGNPROPERTIES
Fb (psi) 900 NDSSupp.Table 4A
CD 1.6 NDSTable2.3.2
CR 1.25 SDPWS Table 3.1.1
CF 1.2 NDSSupp.Table 4A
E(psi) 1600000 NDSSupp.Table 4A
Sx (in3) 13.1 CalculatedNDS3.3-4
I(in4) 47.6 CalculatedNDS3.3-3
![Page 86: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/86.jpg)
Soisourstudgoingtowork?
Twoofthemostcriticaldesignparametersarebendinganddeflection.
Studswork!
IBCTable1604.3footnotef
![Page 87: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/87.jpg)
• GCp:1.00(Figure30.4-1)• GCpi:0.18(Table26.11-1)• qh =0.00256KzKztKdV2
§ Kh :0.70- Table30.3-1§ Kzt :1.00- Figure26.8-1§ Kd :0.85- Table26.6-1§ V:130mph
• qh =25.74psf• p=25.74psf(1.0+0.18)=30.37psf• 0.6W=0.6(30.37)=18.22psf
Runningthenumbers– Zone5
![Page 88: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/88.jpg)
Whataboutcornerzones?
Deflectionchecknogood– solution:reduceloadsoneachstud
IBCTable1604.3footnotef
![Page 89: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/89.jpg)
12”StudSpacing
Sincestuddepthcannotbeincreasedconsiderreducingstudspacingto12”inallZone5areas:
Studswork!– Use2x8@16”o.c.typical,use2x8@12”o.c.incorners(Zone5areas)
IBCTable1604.3footnotef
![Page 90: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/90.jpg)
WallDesignConsiderations
Fortallwallswhileitislesslikelyforcombinedbendingandaxialtocontrol
• MainWindForceLoadsmaybe
utilized
• Loadcombinations(ASCE7Chpt 2)
for:
§ wind+deador
§ dead+0.75live+0.75rooflive
(orsnow)
D,L,S
W
![Page 91: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/91.jpg)
WallDesignConsiderations
Forotherdesignissuesseethearticle:
• ConsiderationsinWindDesignofWoodStructures
• FreedownloadfromAWCavailableat:http://www.awc.org/pdf/codes-standards/publications/archives/AWC-
Considerations-0310.pdf
![Page 92: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/92.jpg)
WallStudDesignAidWesternWoodProductsAssociation(WWPA)DesignSuite:
http://www.wwpa.org/TECHGUIDE/DesignSoftware/tabid/859/Default.aspx
![Page 93: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/93.jpg)
Overview
• Wind• CalculatingWindLoads• Uplift• WallDesign• Diaphragms• Shearwalls
![Page 94: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/94.jpg)
DiaphragmDesign
![Page 95: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/95.jpg)
WindLoadDistributiontoDiaphragm
WINDINTODIAPHRAGMS
WINDSURFACELOADSONWALLS
![Page 96: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/96.jpg)
WindLoadPaths
WINDINTODIAPHRAGMSASUNIFORMLINEARLOADS
![Page 97: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/97.jpg)
WindLoadPaths
DIAPHRAGMSSPANBETWEEN
SHEARWALLS
WINDINTOSHEARWALLSASCONCENTRATEDLOADS
![Page 98: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/98.jpg)
StudtoDiaphragm
WINDLOAD
DIAPHRAGMSHEATHING
Floor/Roofframingperpendiculartowalls
FLOORJOIST
![Page 99: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/99.jpg)
StudtoDiaphragm
WINDLOAD
DIAPHRAGMSHEATHING
Floor/Roofframingparalleltowalls(addblocking)
FLOORJOIST
BLOCKING
![Page 100: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/100.jpg)
VisualCue
VisualCue:FloorBeaminPlan=DiaphragminElevation
FloorBeam
FloorBeam
FloorBeam
FloorJoists
FloorFramingPlan
FloorJoists
![Page 101: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/101.jpg)
VisualCue
VisualCue:FloorBeaminPlan=DiaphragminElevation
Diaphragm
Diaphragm
Foundation
WallStuds
WallFramingElevation
WallStuds
![Page 102: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/102.jpg)
Floor- BendingMember
• SimplySupportedMember:loadingcausescompressioninoneedgeofmember,tensioninotheredge
Compressionedge
Tensionedge
Loadingdirection
ReactionReaction
![Page 103: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/103.jpg)
Diaphragm– BendingMember
Tensionedge
Compressionedge
![Page 104: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/104.jpg)
WindLoadPath- Lateral
•Diaphragmactslikeadeepbeam.• Sheathingcarriesshearforces• ChordshaveT&Cforces• Rimboardtransfersshear
DIAPHRAGM
![Page 105: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/105.jpg)
UnblockedDiaphragm
![Page 106: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/106.jpg)
BlockedDiaphragm
![Page 107: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/107.jpg)
ChordForces
SPLICEINRIMBOARD
LAPINTOPPLATEPROVIDESCONT.TENSILERESISTANCE
TENSILEFORCE
![Page 108: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/108.jpg)
AssumeBasicWindSpeed=115mphUltimate
ExposureB
DiaphragmDesign
• Capacity
Shearwall Design
• Conventional
• ForceTransferAroundOpening
• PerforatedShearwall
Example:RetailRestaurant
![Page 109: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/109.jpg)
RetailRestaurant– DiaphragmDesign
84’
34’
10’6’ 8’5’
6’
6’
6’
6’
6’
3’3’
4’
29’24’
CriticalShearwall atfrontofbuilding
CheckDiaphragmforwindloadson84’wall
![Page 110: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/110.jpg)
RetailRestaurant– DiaphragmDesign
CriticalShearwall atfrontofbuilding
CheckDiaphragmforwindloadson84’wall
84’
34’
10’6’ 8’5’
6’
6’
6’
6’
6’
3’3’
4’
29’24’
![Page 111: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/111.jpg)
DiaphragmAspectRatios
SDPWSTABLE4.2.4
TYPE- MAXIMUMLENGTH/WIDTHRATIO
Foran84x34diaphragmtheaspectratiois2.5<3.
DiaphragmaspectratioisOK.
Woodstructural panel,unblocked 3:1
Woodstructural panel,blocked 4:1
Single-layerstraightlumbersheathing 2:1
Single-layerdiagonallumbersheathing 3:1
Double-layerdiagonallumbersheathing 4:1
![Page 112: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/112.jpg)
CalculatingMWFRSWindLoadsCalculatewindpressureusingDirectionalMethod(ASCE7Chpt 27)
p=qh[(GCpf)-(GCpi)]
qh =0.00256*0.57*1.0*0.85*1152*1=16.4psf
GCpf =0.85*[0.8– (-0.3)]=0.935
GCpi =0.18- 0.18=0
p=(16.4psf)(0.935)=15.34psf
0.6*W=0.6*15.34=9.2 psf onwalls
Usemin9.6psf perASCE27.1.5
ASCE7-10Figure27.4-1
![Page 113: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/113.jpg)
ParapetDesign– Figure27.6-2
Atparapetswindwardandleewardpressuresoccuroneachparapet.
Section27.4.5:Pp =q(GCpn)GCpn =1.5Windwardparapet,-1.0LeewardparapetWindwardParapetGCpf is1.5:16.4*1.5*0.6=14.76psfLeewardParapetGCpf is1.0:16.4*1.0*0.6=9.84psfNetParapet=14.76+9.84=24.6psf
![Page 114: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/114.jpg)
RetailRestaurant– DiaphragmDesign
84’
34’
10’6’ 8’5’
6’
6’
6’
6’
6’4’
29’24’
10’
3’
3’
P=(9.6psf*(5’+3’)+(24.6)*3’)*(84’/2)=6,325lb
νdiaphragm=6,325lb/34’νdiaphragm=186plf
P
![Page 115: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/115.jpg)
DiaphragmTypes
CASE1DIAPHRAGM•HigherShearValues•Panelsperpendiculartofloorframingforimprovedperformance
CASES2-6Maybepreferredforlowsheardemandwherechangingframingdirectionhelps•HVACruns•FireBlocking/DraftStopping
RoofTrusses4x8sheathingN-S
![Page 116: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/116.jpg)
DiaphragmTypes
SDPWSTables4.2A&B
![Page 117: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/117.jpg)
DiaphragmCapacity- SDPWSChpt 4
• CapacitiesareNominal:ModifybyASDreductionfactorof2,ModifybyLRFDmultiplicationfactorof0.8
• CapacityisreducedforspecieswithSpecificGravity<0.5• ForSprucePineFirmultiplyby0.92
![Page 118: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/118.jpg)
DiaphragmCapacity:SDPWSTable4.2C
PANELGRADE
COMMONNAILSIZEORSTAPLEf
LENGTHANDGAGE
MINIMUMFASTENERPENETRATIONINFRAMING
MINIMUMPANELTHIICKNESS
MINIMUMNOMINALWIDTHOFFRAMINGMEMBERSATADJOININGPANELEDGESANDBOUNDARIESg
NAILSPACINGATALLPANELEDGES
Case1(Nounblockededgesorcontinuousjointsparalleltoload)
Allotherconfigurations(Cases2,3,4,5and6)
Sheathing&singlefloor
8d(2½“x0.131”)
13/8”
7/16”
2IN. 6IN. 460(Seismic)645(Wind)
340(Seismic)475(Wind)
3IN. 6IN. 510(Seismic)715(Wind)
380(Seismic)530(Wind)
CapacityisreducedforspecieswithSpecificGravity<0.5.ForSprucePineFirmultiplyby0.92
Capacity =(645plf)(0.92)/2=297plf297plf >186plf,diaphragmisadequatewithsheathing&fasteningasshownabove
![Page 119: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/119.jpg)
TransferringDiaphragmShearForces
BLOCKTOTRANSFERFORCES
UPPERWALL
![Page 120: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/120.jpg)
TransferringDiaphragmShearForces
BLOCKTOTRANSFERFORCES
PARAPET
NOTE:PARAPETKICKERSMAYBEREQUIREDFORTALLTRUSSPARAPETS
![Page 121: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/121.jpg)
TransferringDiaphragmShearForces
SHEARWALLBELOW
SHEARFORCEFROMDIAPHRAGM
RIMJOISTPROVIDESDIAPHRAGMLOAD
TRANSFER
![Page 122: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/122.jpg)
DiaphragmtoShearwall Fastener
RIMBOARD
FLOORJOIST
TOPPLATE
TOENAIL150plf (ASD)LIMITINSDCD,E,F(SDPWS4.1.7)
METALCLIPSFORADD’LSTRENGTH
![Page 123: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/123.jpg)
RoofDiaphragmtoShearwall
BLOCKINGTRANSFERSSHEARFORCESFROMROOFDIAPHRAGMTO
TRUSS
DIAPHRAGM
SHEARWALL
TRUSSTOWALLCONNECTION
COMPLETESLOADPATH
![Page 124: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/124.jpg)
RoofDiaphragmtoShearwall
BLOCKINGTOTRANSFERSHEAR
FORCES
DIAPHRAGM
SHEARWALL
![Page 125: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/125.jpg)
• Diaphragmscanbeidealizedasflexible,semi-rigid,orrigid
• ASCE7-10Section26.2statesthatdiaphragmsconstructedofwoodstructuralpanelsarepermittedtobeidealizedasflexible
WoodEducationInstitute
DiaphragmFlexibility
![Page 126: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/126.jpg)
DiaphragmFlexibilitySomebuildinglayoutsmayrequirediaphragmdesigntoaccountforcantilevers,oropenfrontstructures.• Trendsinmid-rise,multi-familybuildingstowardfewer
exteriorshearwallsmoveintosemi-rigid&rigidmodeling
Cant.
SWSWSWSW
SWSWSWSWSW
SW
NoexteriorShearwalls
Cor
ridor
onl
y sh
ear w
alls
Offs
et s
hear
wal
ls
![Page 127: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/127.jpg)
DiaphragmsofOpenFrontStructures
ExamplesofOpenFrontStructuresper2015SDPWSFigure4A
![Page 128: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/128.jpg)
OpenFrontStructures(SDPWS4.2.5)
• Canidealizediaphragmasrigidifmax.in-planediaphragm
deflectionis≤2xavg.storydriftofverticalelements
• Ifnotidealizingasflexibleorrigid,mayusesemi-rigidanalysis,
distributesshearbasedonrelativestiffnessofbothdiaphragm
andverticalresistingelements
• Commontouseenvelopeanalysisinlieuofsemi-rigidanalysis• 2015SDPWS:DiaphragmCantilever≤35feet
AdditionalConsiderations:
• L/WRatio
• Irregularities&TorsionalEffects
• Diaphragmdeflections,especiallyatcorners
![Page 129: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/129.jpg)
Shearwall &DiaphragmDeflection
Whencalculatingshearwall anddiaphragmdeflections,valuesofapparentshearstiffness,Ga,arerequired,butarenotprovidedforwinddesigninSDPWS
![Page 130: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/130.jpg)
Shearwall &DiaphragmDeflectionAWCFAQ:Cantheeffectiveshearstiffnessvalues,Ga,inSDPWSbeusedforcalculationofdiaphragmandshearwalldeflectionsduetowindloads?
Valuesofapparentshearstiffness,Ga,aretabulatedinseismiccolumnsofthe SDPWS tofacilitatecalculationofseismicstorydriftinaccordancewithASCE7MinimumDesignLoadsforBuildingsandOtherStructures.ValuesofGa areequallyapplicableforcalculation ofthesheardeformationcomponentoftotaldeflectionduetowindloadsuptotheASDwindunitshearvaluecalculatedasvw/2.0.Thislevelofunitshearforwindisidenticalto1.4timestheASDseismicunitshearcapacityforwhichapparentshearstiffnessvalueswereoriginallydeveloped.
http://awc.org/faqs/general/can-the-effective-shear-stiffness-values-ga-in-special-design-provisions-for-wind-and-seismic-%28sdpws%29-be-used-for-calculation-of-diaphragm-and-shear-wall-deflections-due-to-wind-loads
![Page 131: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/131.jpg)
Overview
• Wind• CalculatingWindLoads• Uplift• WallDesign• Diaphragms• Shearwalls
![Page 132: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/132.jpg)
WindLoadDistributiontoShearwalls
WINDINTODIAPHRAGMSWINDINTOSHEARWALLS
WINDSURFACELOADSONWALLS
![Page 133: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/133.jpg)
Shearwalls
HOLD-DOWN
WSPSHEATHING
ANCHORBOLTS
WOODSTUDS
![Page 134: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/134.jpg)
WSPShearwall Capacity• CapacitieslistedinAWC’sSpecialDesign
ProvisionsforWindandSeismic(SDPWS)• Sheathedshearwallsmostcommon.Canalso
usehorizontalanddiagonalboardsheathing,gypsumpanels,fiberboard,lathandplaster,andothers
• Blockedshearwallsmostcommon.SDPWShasreductionfactorsforunblockedshearwalls
• Notethatcapacitiesaregivenasnominal:mustbeadjustedbyareductionorresistancefactortodetermineallowableunitshearcapacity(ASD)orfactoredunitshearresistance(LRFD)
![Page 135: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/135.jpg)
Shearwall Capacity- SDPWSChpt 4
![Page 136: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/136.jpg)
WindLoadscreateshear(sliding)andrackingforcesonastructure
Slidingresistedbyshearwall baseanchorageRackingresistedbyshearpanel&fasteners
Shearwall Functions
![Page 137: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/137.jpg)
ShearWallComponents:WallFraming
Strut/collector
WallFraming(Studs)
BlockingBetweenStudsatAllPanelEdges
WallTopPlates
WallSolePlate
Note:Canuse“un-blocked”wallbutcapacitiescanbesignificantlylower:SDPWS4.3.3
![Page 138: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/138.jpg)
RackedShearwall
EDGENAILINGPROVIDESRACKINGRESISTANCE
![Page 139: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/139.jpg)
ShearWallComponents:WSP&Fasteners
Strut/collector
FieldorIntermediateNailing– Typ.12”o.c.
BoundaryNailing–Typ.2”– 6”o.c.
BoundaryNailing:Attachesall4edgesofeverypaneltowallframing(studs,blocking,top&soleplates)
FieldorIntermediateNailing:Attachespaneltointermediatewallframing(studs)notalongpaneledges
SheathingPanelsOSBorPlywood
![Page 140: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/140.jpg)
PanelFasteners
![Page 141: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/141.jpg)
Shearwalls
ANCHORBOLTSTOFOUNDATION
PREVENTSLIDING!
![Page 142: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/142.jpg)
Duetocantilevernatureofshearwalls,overturningforcesarealsogenerated
Overturningforcesareresistedbytension/compressioncouple–tensionportionresistedbydeadloadsandholddownanchors
Shearwalls - Overturning
![Page 143: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/143.jpg)
Floor- CantileverMember
Tensionedge
Compressionedge
![Page 144: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/144.jpg)
Shearwall - CantileverMember
Tensionedge
Compressionedge
![Page 145: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/145.jpg)
Hold-DownsResistEndUplift
HOLD-DOWNS
![Page 146: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/146.jpg)
ShearWallComponents:BaseAnchorage,EndPosts&HoldDowns
Strut/collector
SolePlateUniformAnchorage:Transfersshearfromwallsoleplatetofloor/wallorfoundationbelow.
SolePlateUniformAnchorage(Nails,Screws,Anchor
Bolts)
WallEndPost&HoldDown:Transfersverticaltension&compressionforcestofloor/wallorfoundationbelow.
WallEndPost&HoldDown
WallEndPosts(SizedforTension&Compression)
![Page 147: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/147.jpg)
Shearwall HoldDowns
Source:DartDesignInc.com
Source:strongtie.com
BucketStyle
![Page 148: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/148.jpg)
Shearwall HoldDowns
Straps
Source:strongtie.com
![Page 149: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/149.jpg)
Shearwall HoldDowns
ContinuousRodTieDownswithShrinkageCompensation
Devices Source:hardyframe.com
Source:cteg.com
![Page 150: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/150.jpg)
Shearwall Placement- Symmetrical
INTHISCASEDRAGSTRUTSCARRYLITTLE LOAD
TOPPLATE– NTSDRAGSTRUT
SHEARWALLS
WINDWARD
LEEWARD
![Page 151: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/151.jpg)
Shearwall Placement– LargeDragStruts
INTHISCASEDRAGSTRUTSTRANSFERLEEWARDLOAD
TOPPLATE– NTSDRAGSTRUTSHEARWALLS
WINDWARD
LEEWARD
![Page 152: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/152.jpg)
DragStruts&IsolatedWalls
INSOMECASESDOUBLETOPPLATEISINADEQUATE
WHATTOWATCHFOR:
• ISOLATEDSWWITHHEAVYNAILING• NOSHEARWALLSWITHIN10’OFWALLCORNER
![Page 153: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/153.jpg)
LateralForceResistingSystem
![Page 154: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/154.jpg)
Shearwalls inaLine- Stiffness• Windloadstomultipleshearwalls inthesamelinearedistributed
basedonshearwall stiffness• Ifwallshavethesameframing&sheathing,assumedtohavethe
sameper-footstiffness&loadsaredistributedbasedonwalllength• Eg.5’longwallreceives5/(5+12)=29%oftotalload
12’longwallreceives12/(5+12)=71%oftotalload
SHEARWALLLENGTHSDETERMINESTIFFNESS&LOADSHARING5’12’
![Page 155: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/155.jpg)
Shearwall AspectRatio
NDSSDPWSTABLE4.3.4
MAXIMUMSHEARWALLDIMENSIONRATIOS
SeeSDPWSTable4.3.4forfootnotes
Woodstructural panels,blocked Forotherthanseismic:3½:11
Forseismic: 2:11
Woodstructural panels,unblocked 2:1
Diagonalsheathing, single 2:1
StructuralFiberboard 3½:13
Gypsumboard,portland cement plaster 2:12
L
H
AR=H/L
![Page 156: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/156.jpg)
EngineeredShearWallSystemsw/WSP
SolidorSegmentedWalls
PerforatedWallsForceTransferAround
OpeningsWalls
![Page 157: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/157.jpg)
RetailRestaurant– Shearwall Design
84’
34’
10’6’ 8’5’
6’
6’
6’
6’
6’4’
29’24’
10’
3’
3’
P =7,602lb – fromdiaphragmcalcs usingDirectionalMethod
Let’sseewhathappenswhenweuseEnvelopeMethodtocalculateMWFRSloadstofrontshearwall
P
![Page 158: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/158.jpg)
CalculatingMWFRSWindLoadsCalculatewindpressureusingEnvelopeMethod(ASCE7Chpt28)
p=qh[(GCpf)-(GCpi)]
qh =0.00256*0.70*1.0*0.85*1152*1=20.14psf
GCpf (Zones1&4) =0.4– (-0.29)=0.69(ASCE7Fig.28.4-1)
GCpf (Zones1E&4E) =0.61– (-0.43)=1.04(ASCE7Fig.28.4-1)
GCpi =0.18- 0.18=0
P1&4=(20.14psf)(0.69)=13.9psf;0.6*W=0.6*13.9=8.3psfwallstyp.
P1E&4E=(20.14psf)(1.04)=20.9psf;0.6*W=0.6*20.9=12.5psf wallscrnr
ASCE7-10Figure28.4-1
![Page 159: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/159.jpg)
CalculatingMWFRSWindLoads
ASCE7-10Figure28.4-1
a=Lesserof:
• 10%leasthorizontaldimension(LHD)34’*0.1=3.4’
• 0.4h=0.4*13’=5.2’.Butnotlessthan:
• 0.04LHD=1.4’or3’
Usea=3.4’forzones1E&4E
2a=3.4’*2=6.8’
![Page 160: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/160.jpg)
ParapetDesign– Section28.4.2
Atparapetswindwardandleewardpressuresoccuroneachparapet.
Section28.4.2:Pp =q(GCpn)GCpn =1.5Windwardparapet,-1.0LeewardparapetWindwardParapetGCpf is1.5:20.14*1.5*0.6=18.12psfLeewardParapetGCpf is1.0:20.14*1.0*0.6=12.08psfNetParapet=18.12+12.08=30.2psf
![Page 161: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/161.jpg)
RetailRestaurant– Shearwall Design
84’
34’
10’6’ 8’5’
6’
6’
6’
6’
6’4’
29’24’
10’
3’
3’
P
6.8’12.5psf8.3psf
77.2’
P=(8.3psf*(5’+3’)+(30.2)*3’)*(84’/2)+((12.5psf-8.3psf)*(5’+3’))*6.8’*(77.2’/84’)=6,804lb(forcomparison:Directionalmethodgaveus6,325lb)
![Page 162: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/162.jpg)
Shearwall AspectRatios
10’
3’
3’34’
6’ 6’ 6’ 6’ 6’2’ 2’
10’
• CheckAspectRatios:AssumeblockedWSPShearwall• 10’/2’=5>3.5;Inadequate• 10’/6’=1.67<3.5;OK
FrontWallElevation
![Page 163: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/163.jpg)
• CheckAspectRatios:AssumeblockedWSPShearwall• 10’/2’=5>3.5;Inadequate• 10’/6’=1.67<3.5;OK
Shearwall AspectRatios
10’
3’
3’34’
6’ 6’ 6’ 6’ 6’2’ 2’
10’
νshearwall =6,804lb/12’=567plf
![Page 164: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/164.jpg)
ConventionalShearwall Capacities
νshearwall =567plf
Assume15/32”,StructuralIsheathingattachedwith8dnails
NominalTabulatedCapacity=1540plfAdjustedASDCapacity =(1370plf)(0.92)/2=630plf630plf >567plf,OK8dnailsat3”o.c.acceptable
PANELGRADE FASTENERTYPE&SIZE
MINIMUMPANELTHIICKNESS
MINIMUMFASTENERPENETRATIONINFRAMING
NAIL SPACINGATALLPANELEDGES
PANEL EDGEFASTENERSPACING
WoodStructuralPanels–Sheathing
8d(2½“x0.131”)
15/32” 13/8” 3IN. 980(Seismic)1370(Wind)
SDPWSTable4.3A
![Page 165: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/165.jpg)
DesignTableDetails– 16”o.c.Studs
• Spacefasteners12inchesoncenteronintermediatesupports(SDPWS4.3.7.1.3)
• Ifnailspacingis2”o.c.use3inchnominalframing (SDPWS4.3.7.1.4)
• If10dnailsareutilizedalongwith3incho.c.edgenailingusenominal3xframing(SDPWS4.3.7.1.4)
• Ifnominalunitshearoneithersideofwallexceeds700plf inSDCD,E,orF,usenominal3xframing(SDPWS4.3.7.1.4)
![Page 166: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/166.jpg)
ConventionalShearwall Overturning
νshearwall =567plfHolddownsrequiredatshearwallsT=νhT=567plf*10’=5,670lb
Holddowncapacity=7,045lbManyavailableprefabricatedholddownswithcapacitieslistedbymanufacturers
34’
6’ 6’ 6’ 6’ 6’2’ 2’
10’
![Page 167: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/167.jpg)
Hold-DownAnchor
![Page 168: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/168.jpg)
ConventionalShearwall Overturningνshearwall =567plfPostsarealsorequiredatendsofthewalltoresistcompressionforcesC=T=νhC=567plf*10’=5,670lb
6’ 6’ 6’ 6’ 6’2’ 2’
10’
SizepostforbearingonwallsoleplateAssume2x6wall,Requiredpostwidth=5,670lb/(565psi)(5.5in)=1.8in;Use2-2x6postmin.
![Page 169: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/169.jpg)
ConventionalShearwall BaseAnchorage• νshearwall =567plf• ½”AnchorBoltcapacityforwoodbearing=680lb*1.6=1,088lb
perNDSTable11E• Spacing=1088lb/567plf =1’-11”o.c.max.
![Page 170: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/170.jpg)
Hold-Downs:Segmentedv.PerforatedSegmentedShearwall
PerforatedShearwall
![Page 171: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/171.jpg)
PerforatedShearWallMethod
HOLDDOWNSATENDOFWALL
WSPSHEATHING
Fewerholddownsrequired,shearcapacityisreduced
Uniformupliftatbaseofwallrequired– magnitude=shearforce– SDPWS4.3.6.4.2.1
![Page 172: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/172.jpg)
• CheckAspectRatios:AssumeblockedWSPShearwall• 10’/2’=5>3.5;Inadequate• 10’/6’=1.67<3.5;OKUseonlyfullheightsheathedsectionstoresistshear
PerforatedShearwall Design
10’
3’
3’34’
6’ 6’ 6’ 6’ 6’2’ 2’
10’
νshearwall =6,804lb/12’=567plf
TotalPerforatedShearwall
![Page 173: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/173.jpg)
PerforatedShearwall CapacityWallhas12’/18’=67%fullheightsheathing,max.openingH=6’-8”
Multiplycapacityby0.75foropening2H/3
Reducedcapacityis630plf*0.75=473plf <567plf,Inadequate
SDPWSTable4.3.3.5
![Page 174: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/174.jpg)
PerforatedShearwall Capacity
νshearwall =567plf
Tryreducingnailspacingto2”with8dnails– willrequire3xframing
NominalTabulatedCapacity=1790plfAdjustedASDCapacity=(1790plf)(0.92)(0.75)/2=618plf618plf >567plf,OK8dnailsat2”o.c.acceptableforperforatedwall
PANELGRADE FASTENERTYPE&SIZE
MINIMUMPANELTHIICKNESS
MINIMUMFASTENERPENETRATIONINFRAMING
NAIL SPACINGATALLPANELEDGES
PANEL EDGEFASTENERSPACING
WoodStructuralPanels–Sheathing
8d(2½“x0.131”)
15/32” 13/8” 2IN. 1280(Seismic)1790(Wind)
SDPWSTable4.3A
![Page 175: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/175.jpg)
PerforatedShearwall Overturning
34’
6’ 6’ 6’ 6’ 6’2’ 2’
10’
νshearwall =567plfHolddownsrequiredatendsofperforatedwallT=νh/CoT=567plf*10’/0.75=7,560lb
Holddowncapacityfromsegmentedwalloption=7,045lb,Inadequate– needtoselecthighercapacityholddown
![Page 176: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/176.jpg)
PerforatedShearwall Uplift
34’
6’ 6’ 6’ 6’ 6’2’ 2’
10’
νshearwall =567plf/0.75=756plf,usesamemagnitudeforuniformupliftatfullheightsegmentsOneoptionistouseanchorboltswithlargewasherstoresistupliftinbearingIfnetwasherarea=8in2,canresist(565psi)(8in2)=4,520lb inuplift• Max.anchorboltspacing=4,520lb/756plf =5’-11”o.c.• Willalsoneedtocheckshearloadsonanchorboltsforcontrolling
case
![Page 177: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/177.jpg)
ForceTransferAroundOpening(FTAO)
HOLDDOWNSATENDSOFWHOLEWALL
WSPSHEATHING
![Page 178: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/178.jpg)
ForceTransferAroundOpening(FTAO)
![Page 179: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/179.jpg)
FTAOShearwallsMethodologies• Shearwall designmethodologywhichaccountsforsheathed
portionsofwallaboveandbelowopenings(perforatedneglects)• Openingsaccountedforbyreinforcingedgesusingstrappingor
framing• SDPWS4.3.5.2providesspecificrequirements
• H/Lratiodefinedbywallpier• Min.wallpierwidth=2’-0”
• Reducednumberofholddowns(onlyatendsoftotalwall)
• Thereare3mainmethodsofFTAOanalysis;SDPWSdoesnotrequireoneparticularmethodbeused,onlythatdesignis“basedonarationalanalysis”• DragStrut,CantileverBeam,&DiekmannDesignOptions
![Page 180: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/180.jpg)
FTAOShearwallsDragStrutDesignMethodology• Forcesarecollectedandconcentratedintotheareasaboveand
belowtheopenings• Strapforcesareafunctionofopeningandpierwidths
APAFormM410
![Page 181: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/181.jpg)
FTAOShearwallsCantileverBeamDesignMethodology• Forcesaretreatedasmomentcouples• Segmentedpanelsarepiersatsidesofopenings• Strapforcesareafunctionofwallheightaboveandbelow
openingsandpierwidths
APAFormM410
![Page 182: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/182.jpg)
FTAOShearwallsDiekmann DesignMethodology• Assumeswallbehavesasmonlithic trussorframe• Internalforcesresolvedviaprinciplesofstatics• Wallsectionsonallsidesofopeningareassumedtohaveapoint
ofinflectionatmidlength,producingnoforceintheinnerchordsofthesections
APAFormM410
![Page 183: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/183.jpg)
FTAOShearwall DesignAid
ImagesSource:RISATechnologies
RISATechnologiesdesignsoftwareincludesanoptiontodesignFTAOwoodsheathedshearwalllsusingfiniteelementanalysis(FEM)
![Page 184: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/184.jpg)
Double-SidedShearwalls
High-strengthwoodshearwallscanbedouble-sidedwithWSPsheathingoneachside:SDPWS4.3.3.3SummingShearCapacities:Forshearwallssheathedwiththesameconstructionandmaterialsonoppositesidesofthesamewall,thecombinednominalunitshearcapacity shallbepermittedtobetakenastwicethenominalunitshearcapacityforanequivalentshearwallsheathedononeside(4.3.5.3hasmaxcapacitiesfordouble-sidedperforatedwalls)
![Page 185: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/185.jpg)
Double-SidedShearwalls
Thereisalsoanoptiontohaveasinglesided,doublesheathedshearwall.
TestingandreportbyAPAconcludethatitispermissibletousethecapacityofthewallthesameasiftherewasonelayerofWSPoneachsideofthewallprovidedthatanumberofcriteriaaremetincluding:• Framingmembersatpanel
jointsare3xor2-2x• Minimumnailspacingis4”• Others
![Page 186: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/186.jpg)
OpenFront&NarrowWalls
![Page 187: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/187.jpg)
UsingPrefabShearwalls
Considerations:EngineeredNarrowWallSection
Proprietary
LargeHold-downforces
Deflections
![Page 188: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/188.jpg)
HybridWood/SteelPrefabShearwalls
Source:hardyframe.com
![Page 189: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/189.jpg)
PrefabWallAspectRatios
10’
3’
3’34’
30’2’ 2’
10’
• AspectRatioInadequate• 10’/2’=5>3.5• V=6,804lb• Let’stryaprefabshearwall
![Page 190: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/190.jpg)
PrefabShearwall CapacitiesLOADIS=6,804lb
3,660lb *2panels=7,320lb
![Page 191: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/191.jpg)
PrefabShearwall Anchorage
![Page 192: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/192.jpg)
PrefabShearwall Anchorage
![Page 193: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/193.jpg)
PrescriptivePortalFrameSystems
• SeniorLiving• Apartments/Condos• MixedUse• StudentHousing• AffordableHousing• Hotels
WhereWoodisaviableoption,it’slikelythemostappropriatechoice.
PrescriptiveCodePortalFramesIBC2308.9.3.2
ProprietaryPortalFrames
Source:strongtie.com
![Page 194: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/194.jpg)
PrescriptivePortalFrameSystems
• SeniorLiving• Apartments/Condos• MixedUse• StudentHousing• AffordableHousing• Hotels
WhereWoodisaviableoption,it’slikelythemostappropriatechoice.
APAReportTT-100F
Allowable DesignShearValues
Min.Width(in.)
Max.Height(ft.)
Shear(lb)
168 850
10 625
248 1,675
10 1,125
![Page 195: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/195.jpg)
GypsumShearwalls• LowercapacitiesthanWSPShearwalls (about1/3capacity)• SDPWSTable4.3C,Section4.3.7.5providescapacities&
requirements• NotpermittedinSDCEorF
![Page 196: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/196.jpg)
WSPShearwalls OverGypsum• Fireresistanceratedwallsmayrequiregypsumboardon
eachside• SDPWSTable4.3Bprovidesshearwall capacitiesforwalls
withWSPinstalledover½“or5/8”gypsumboard• Ruleofthumb:samecapacitiesaswithoutgypsumcan
beobtainediffastenerlengthincreased(gouponenailsize;i.e.if8dwithoutgypsum,use10dwithgypsum).
WallFraming
Gypsumboardeachsideofwall
WSPinstalledovergypsum
board
WallSection
![Page 197: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/197.jpg)
Recap
• Wind• CalculatingWindspeeds• Uplift• WallDesign• Diaphragms• Shearwalls
![Page 198: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/198.jpg)
Questions?
ThisconcludesTheAmericanInstituteofArchitectsContinuingEducationSystemsCourse
Visitwww.woodworks.org formoreeducationalmaterials,casestudies,designexamples,aprojectgallery,andmore
![Page 199: 15LS03 Designing Wood-Frame Structures For High Winds V2 · ASCE 7-10 26.2 commentary provides some discussion on uplift & MWFRS vs. C&C. Components receive wind loads directly or](https://reader035.fdocuments.in/reader035/viewer/2022070704/5e8482c574d6855d2554dcc7/html5/thumbnails/199.jpg)
ThispresentationisprotectedbyUSandInternationalCopyrightlaws.
Reproduction,distribution,displayanduseofthepresentationwithoutwrittenpermission
ofthespeakerisprohibited.
©TheWoodProductsCouncil2016
CopyrightMaterials