American standard building code requirements for minimum ...

1 , ,DirectorNATIONALBUREAUOFSTANDARDSMISCEL LANEOUSPUBLICATIONM179 AMERICANSTANDARDBUILDINGCODEREQUIREMENTS FORMINIMUMDESIGNLOADSINBUILDINGSANDOTHER STRUCTURESBySectionalCommitteeonBuilding CodeRequirementsforMinimumDesignLoadsinB uildings A58 UndertheSponsorshipoftheNationalBureauof StandardsIssuedOctober18,1945 ApprovedJune19,1945, :1945 ForsalebytheSuperintendentofDocuments, , , ,live,wind, ,BuildingCodeStandard-ization, ,DirectorSECTIONALCOMMITTEET henersonneloftheSectionalCommitteeonBuil dingCodeRe-n^^^mmimnRDesignLoadsmBuHdrng s-ASS,whichdevelopedthestandard,isasfoll ows:NationalBureauofStandards, ,Chairman,jHCourtney, (Alternate).AmericanSocietyofCivilEngine ersJ*- .BuildingOfficialsConferenceofAmerica-J^ A Easton(Alternate).CoastandGeodeticSurvey , ^SST^' ^:-y^"^^_^^ "EstateBo^ , ^Thompson.

2 ^b -ss-w z"-::-^---? (includingsnowloads) , <6-5, ". (a). (includingsnowloads) ]\ | ~ * AmericanStandardBuildingCodeRequirements forMinimumDesignLoadsinBuildingsandOther StructuresBySectionalCommitteeonBuilding CodeRequirementsforMinimumDesignLoadsinB uildings A58 UndertheSponsorshipoftheNationalBureauof StandardsABSTRACTB uildingCodeRequirementsforMinimumDesignL oadsinBuildingsandOtherStructures(ASA )givesassumptionsfordead,live,wind, ,pre-paredbyAmericanStandardsAssociation SectionalCommitteeA58underthesponsorship oftheNationalBureauofStandards, , Theserequirementsareintendedtogovernassu mptionsfordead,live, , "permanentconstructionandequipment,inclu dingwalls,framing,floors,roofs,permanent par-titions,andstairways, Buildingsorotherstructures,andallartsthe reof,shallbedesignedandconstructedtosupp ortsafelyalloads,includingdeadloads, Whenanexistingbuildingortherstructureise nlargedorotherwisealtered,allportionsthe reofffectedbysuchenlargementoralteration shallbestrengthened,ifecessary, , Inestimatingdeadloadsforpurposesofdesign ,theactualweightsofmaterialsandcon-struc tionsshallbeused, Forinformationondeadloads,seeappendix.

3 Inestimatingdeadloadsforpurposesofdesign ,theweightofplumbingstacksandrisers,elec tricfeeders, (a)Theliveloadsassumedforpurposesofdesig nshallbethegreatestloadsthatprobablywill beproducedbytheintendedoccu-panciesoruse s,providedthattheliveloadstobeconsidered asuni-formlydistributedshallbenotlesstha nthevaluesgiveninthefollowingtable:OCCUP ANCYORUSELIVELOADA partmenthouses:lb/ft2 Privateapartments40 Publicstairways100 Assemblyhalls:Fixedseats60 Movableseats100 Corridors,upperfloors100 Corridors:Firstfloor100 Otherfloors, ,public100 Dwellings40 Hospitalsandasylums:Operatingrooms60 Privaterooms40 Wards_*40 Publicspace80 Hotels:Guestrooms1_40 Corridorsservingpublicrooms100 Publicrooms100 Loftbuildings__-_125 Manufacturing,light125 Officebuildings:Offices80 Lobbies100 Schools:Classrooms40 Corridors100 Stores:125 Theaters.

4 Aisles,corridors,andlobbies100 Orchestrafloor60 Balconies60 Stagefloor150 MinimumDesignLoadsinBuildings(b)Whenoccu panciesorusesnotlistedaboveareinvolved, Forinformationonliveloads,seeappendix, Inofficebuildingsorother'buildingswherep artitionsmightbesubjecttoerectionorrearr angement,pro-visionforpartitionweightsha llbemade,whetherornotpartitionsareshowno ntheplans, Inthedesignoffloors, ,orthefollowingminimumcon-centrations, ){ ,includingcorridors2, " Whentheconstructionissuchthatthestruc-tu ralelementsthereofacttogetherinthenature ofanelasticframeduetotheircontinuityandt herigidityoftheconnections,andtheliveloa dexceeds150poundspersquarefootortwicethe deadload, TheliveloadsspecifiedinSection3-1(a) ,suchasthoseresultingfrommovingmachinery ,elevators,craneways,vehicles,etc.}

5 , (a)Noreductionshallbeappliedtotheroofliv eload.(b)Forliveloadsof100poundsorlesspe rsquarefoot, , :I*=100> <Sz'inwhich#=reductioninpercentZ ?=deadloadpersquarefootofareasupportedby thememberL= ,noreductionshallbemade,exceptthatthedes ignliveloadsoncolumnsmaybe' Itshallbeunlawfultoplace,orcauseorpermit tobeplaced, 4524 MiscellaneousPublications, Ineverybuildingorotherstructure,orpartth ereof,usedformercantile,business,industr ial,orstoragepurposes,theloadsapprovedby thebuildingofficialshallbemarkedonplates ofapproveddesignwhichshallbesuppliedands ecurelyaffixedIqytheownerofthebuilding,o rhisdulyauthorizedagent, ,iflost,removed,ordefaced, (includingsnowloads).(a)Ordinaryroofs,ei therflatorpitched,shallbedesignedforaloa dofnotlessthan20poundspersquarefootofhor izontalprojectioninadditiontothedeadload ,andinadditiontoeitherthewindorearthquak eload, ,themapshowninfigure1intheappendixshould beconsultedandtheindicatedsnowloadforthe *locality,iflarger,sub-stitutedforthismi nimum.

6 (b) (a)Stairtreadsshallbedesignedtosupportau niformlydis-tributedloadof100poundspersq uarefoot,orconcentratedloadsof300poundss paced3feetcentertocentereachoccupyingana rea1footwidebythedepthofthetread,whichev erwillproducethegreaterstresses.(b)Sidew alksshallbedesignedtosupporteitheraunifo rmlydistributedloadof250poundspersquaref oot,oraconcentratedloadof8,000poundsonan area2%feetsquareplacedinanyposition,whic heverwillproducethegreaterstresses.(c)Dr ivewaysshallbedesignedtosupportauniforml ydistributedloadof100poundspersquarefoot forvehiclesweighinglessthan3tonswithload ,150poundspersquarefootforvehiclesweighi ng3to10tonswithload,200poundspersquarefo otforvehiclesweighingover10tonswithload, oraconcentratedloadequaltothemaximumexpe ctedwheelloadonanarea2){feetsquareplaced inanyposition,whicheverwillproducethegre aterstresses.}

7 (d)Accessibleceilings,scuttles,andribsof skylightsshallbedesignedtosupportaconcen tratedloadof200poundsoccupyinganarea2){f eetsquare,andsoplacedastoproducemaximums tressesintheaffectedmembers.(e)Stairwaya ndbalconyrailings,bothexteriorandinterio r, Inthedesignofbasementwallsandsimilarappr oximatelyverticalstructuresbelowgrade, ,orthewhole,oftheadjacentsoilisbelowafre e-watersurface,computationsshallbebasedo ntheweightofthesoildimin-ishedbybuoyancy , Inthedesignofbasementfloorsandsimilarapp roximatelyhorizontalconstructionbelowgra de,theupwardpressureofwater,ifany, Buildingsorotherstructuresshallbedesigne dandconstructedtowithstandthehorizontalp res-suresshowninthefollowingtable, *Lessthan50_ _____2050to9924100to19928200to29930300to 39932400to49933500to59934600to79935800to 999361,000to1,199371,200to1,399381,400to 1,599391, , (indicated63bya4-cupanemome-ter)at30feet fromtheground.}

8 < Every,exteriorwallshallbedesignedandcon-'structedtowithstandthepressuresspecifiedinSection5-1,MinimumIDesignPressures, (a)Theroofsofallbuildingsorotherstructuresshallbedesignedandconstructedtowithstandpressures,actingoutwardnormaltothesurface, ,andthepres-sureassumedontheentireroofarea.(b)Roofsorsectionsofroofswithslopesgreaterthan30 shallbedesignedandconstructedtowithstandpressures,actinginwardnormal5 MiscellaneousPublications,NationalBureauofStandardstothesurface,equaltothosespecifiedfortheheightzoneinwhichtheroofislocated,andappliedtothewindwardslopeonly.(c)Overhangingeavesandcornicesshallbedesignedandcon-structedtowithstandoutwardpressuresequaltotwicethosespecifiedinSection5-1,MinimumDesignPressures.(d)Adequateanchorageoftherooftowallsandcolumns,andofwallsandcolumnstothefoundationstoresistoverturning,uplift,andsliding, Chimneys,tanks,andtowersshallbedesignedandconstructedtowithstandthepressuresspecifiedinSection5-1,Mini-mumDesignPressures,multipliedbythefollowingfactors, (a)Signsinwhichtheprojectedareaexposedtowindconsistsof70percentormoreofthegrossareaasdeterminedbytheover-alldimensionsshallbeclassedassolidsigns;thoseinwhichtheprojectedexposedarea"isderivedfromopenletters,figures,strips,andstruc-turalframingmembers,theaggregatetotalareaofwhichislessthan70percentofthegrossareasodetermined,shallbeclassedasopensigns.

9 (b)Allsignsshallbedesignedandconstructed towithstandthehorizontalpressuresshownin thefollowingtableappliedtotheprojectedex posedarea,allowingforwindfromanydirectio n:DesignwindpressuresHeightfromgroundtot opofsignWindpressureSolidsigns(alltypes) Opensigns(alltypes)ftlb/ft>Ib/fVLessthan 50 ,000to1,19946651,200to1,39948671,400to1, 59949681,600andover_____5070 Solidgroundsignslessthan50ftinheightshal lbedesignedandconstructedtowithstandawin dpres-sureofnotlessthan15lb/ft*.bOpengro undsignslessthan50ftinheightshallbedesig nedandconstructedtowithstandawindpres-su reofnotlessthan25 Completerequirementsforsignsarebeingdeve lopedbySectionalCommitteeonBuildingCodeR equirementsforSignsandOutdoorDisplayStru ctures (a)Noallowanceshallbemadefortheshielding effectofotherbuildingsorstructures.

10 (b)Ifthebuildingorotherstructureisonamou ntain,oceanpromontory,orinanyotherlocati onconsideredbythebuildingofficialtobeunu suallyexposed,higherwindpressuresmaybe^ Forcombinedstressesduetowind,dead,live,a ndsnowloads,theallowablestressmaybeincre ased33} percentprovidedthesectionthusfoundisatle astasstrongasthatrequiredfordead,live, (a)Theoverturningmomentduetothewindloads hallnotex-ceed66%percentofthemomentofsta bilityofthebuildingorotherstructuredueto thedeadloadonly, (b)Whenthetotalresistingforceduetofricti onisinsufficienttopreventsliding, Everybuildingorotherstructure,exceptafar mbuildingorlikestructure, Forcombinedstressesduetothelateralloadsp ecifiedinSection6-1togetherwithdead,live ,andsnowloads,theallowablestressesmaybei ncreased50percentprovidedthesectionIthus foundisatleastasstrongasthatrequiredford ead,live, ,dead,live,andsnowloads, Theverticalstructuralunitsofabuildingoro therstructurethatresistlateralloadshallb esoarrangedthat,inanyhorizontalplane,the ircenterofrigiditywillbecoincidentwithth ecenterofgravityofthedeadloadsofthebuild ingorotherstructure, , Thetotalshearatanylevelduetothelaterallo adshallbeassumedtobedistributedtothevert icalresistingunitsatthatlevelinproportio ntotheirrigidities, ,tank.