Chapter 1

DEFINITIONSANDGENERALEQUIREMENTS

1.1 INTRODUCTION

1.1.1 SCOPEThe definitions providing meanings of different terms and general requirements for the structural design ofbuildings,structures,andcomponents thereofarespecified in thischapter.These requirementsshallapply toallbuildingsand structuresor theircomponents regulatedby thiscode.Allanticipated loads required forstructuraldesign shallbedetermined in accordancewith theprovisionsofChapter2.Designparameters required for thestructuraldesignoffoundationelementsshallconformtotheprovisionsofChapter3.Designofstructuralmembersusingvariousconstructionmaterialsshallcomplywith the relevantprovisionsofChapters4 through13.TheFPSequivalentsoftheempiricalexpressionsusedthroughoutPart6arelistedinAppendixA.

ThisCodeshallgoverninallmatterspertainingtodesign,construction,andmaterialpropertieswhereverthisCodeis in conflictwith requirements contained inother standards referenced in thisCode.However, in special caseswherethedesignofastructureoritscomponentscannotbecoveredbytheprovisionsofthiscode,otherrelevantinternationallyacceptedcodesreferredinthiscodemaybeused.

1.1.2 DEFINITIONSThefollowingdefinitionsshallprovidethemeaningofcertaintermsusedinthischapter.

BASESHEAR:Totaldesignlateralforceorshearatthebaseofastructure.

BASICWINDSPEED :Threesecondgust speedat10metresabove themean ground level in terrainExposureBdefinedinSec2.4.8andassociatedwithanannualprobabilityofoccurrenceof0.02.

BEARINGWALLSYSTEM:Astructuralsystemwithoutacompleteverticalloadcarryingspaceframe.

BRACEDFRAME:Anessentiallyverticaltrusssystemoftheconcentricoreccentrictypewhichisprovidedtoresistlateralforces.

BUILDINGFRAMESYSTEM:Anessentiallycompletespaceframewhichprovidessupportforloads.

CONCENTRICBRACEDFRAME(CBF):AsteelbracedframedesignedinconformancewithSec10.20.13.or10.20.14.

COLLECTOR :Amemberor elementused to transfer lateral forces from aportionof a structure to the verticalelementsofthelateralforceresistingelements.

BUILDINGS:Structuresthatencloseaspaceandareusedforvariousoccupancies.

DEADLOAD:Theloadduetotheweightofallpermanentstructuralandnonstructuralcomponentsofabuildingorastructure,suchaswalls,floors,roofsandfixedserviceequipment.

DIAPHRAGM :Ahorizontalornearly horizontal systemacting to transmit lateral forces to the vertical resistingelements.Theterm"diaphragm"includeshorizontalbracingsystems.

bsrm.pranoyTypewritten TextPERSONAL COLLECTION OFENGR. PRANOY BARUABANGLADESH STEEL RE-ROLLING MILLS LTDpranoy.barua@gmail.com

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DUALSYSTEM:AcombinationofMomentResistingFramesandShearWallsorBracedFramestoresistlateralloadsdesignedinaccordancewiththecriteriaofSec1.3.2.

ECCENTRICBRACEDFRAME(EBF):AsteelbracedframedesignedinconformancewithSec10.20.15.

HORIZONTAL BRACING SYSTEM : A horizontal truss system that serves the same function as a floor or roofdiaphragm.

INTERMEDIATEMOMENTRESISTINGFRAME (IMRF) :Aconcretemoment resisting framedesigned inaccordancewithSec8.3.10.

LIVELOAD:Theloadsuperimposedbytheuseandoccupancyofabuilding.

MOMENTRESISTING FRAME :A frame inwhichmembersand jointsare capableof resisting forcesprimarilybyflexure.

ORDINARY MOMENT RESISTING FRAME (OMRF) : A moment resisting frame not meeting special detailingrequirementsforductilebehaviour.

PRIMARYFRAMINGSYSTEM:Thatpartofthestructuralsystemassignedtoresistlateralforces.

SHEARWALL:Awalldesignedtoresist lateralforcesparalleltotheplaneofthewall(sometimesreferredtoasaverticaldiaphragmorastructuralwall).

SLENDERBUILDINGSAND STRUCTURES :Buildings and structureshaving aheightexceeding five times the leasthorizontal dimension, or having a fundamental natural frequency less than 1 Hz. For those cases where thehorizontaldimensionsvarywithheight,theleasthorizontaldimensionatmidheightshallbeused.

SOFTSTOREY:Storeyinwhichthelateralstiffnessislessthan70percentofthestiffnessofthestoreyabove.

SPACEFRAME:Athreedimensionalstructuralsystemwithoutbearingwallscomposedofmembersinterconnectedsoastofunctionasacompleteselfcontainedunitwithorwithouttheaidofhorizontaldiaphragmsorfloorbracingsystems.

SPECIALMOMENT RESISTING FRAME (SMRF) : Amoment resisting frame specially detailed to provide ductilebehaviourcomplyingwiththerequirementsofChapter8or10forconcreteorsteelframesrespectively.

SPECIAL STRUCTURALSYSTEM :A structural systemnot listed inTable1.3.1and speciallydesigned to carry thelateralloads.SeeSec1.3.2.5.

STOREY:Thespacebetweenanytwofloorlevelsincludingtheroofofabuilding.Storeyxisthestoreybelowlevelx.

STOREYSHEAR,Vx:Thesummationofdesignlateralforcesabovethestoreyunderconsideration.

STRENGTH:Theusablecapacityofanelementoramembertoresisttheloadasprescribedintheseprovisions.

TERRAIN:Thegroundsurfaceroughnessconditionwhenconsideringthesizeandarrangementofobstructionstothewind.

THREESECONDGUSTSPEED:Thehighestaveragewindspeedovera3seconddurationataheightof10m.ThethreesecondgustspeedisderivedusingDurst'smodelintermsofthemeanwindspeedandturbulenceintensity.

TOWER:Atall,slimverticalstructure.

VERTICALLOADCARRYINGFRAME:Aspaceframedesignedtocarryallverticalgravityloads.

WEAKSTOREY:Storeyinwhichthelateralstrengthislessthan80percentofthatofthestoreyabove.

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1.1.3 SYMBOLSANDNOTATIONThefollowingsymbolsandnotationshallapplytotheprovisionsofthischapter:

D =dead load on a member including self weight and weight of components, materials andpermanentequipmentssupportedbythemember

E =earthquakeload

Fi =lateralforceappliedatleveliofabuilding

h =heightofabuildingorastructureabovegroundlevelinmetres

hi,hn,hx =heightinmetresabovegroundleveltoleveli,norxrespectively

leveli =ithlevelofastructureabovethebase;i=1designatesthefirstlevelabove thebase

leveln =uppermostlevelofastructure

levelx =xthlevelofastructureabovethebase;x=1designatesthefirstlevelabovethebase.

L =liveloadduetointendeduseoroccupancy

l =spanofamemberorcomponent.

Mx =overturningmomentatlevelx

V =thetotaldesignlateralforceorshearatthebase

Vx =thestoreyshearatstoreylevelx

R =response modification or reduction coefficient for structural system given in Table 2.5.7 forseismicdesign.

S =Snowload

T =Fundamentalperiodofvibrationinseconds

W =Loadduetowindpressure.

W =Weightofanelementorcomponent

Z =SeismiczonecoefficientgiveninFig2.5.1orTables2.5.2or2.5.3

=Storeylateraldrift.

1.2 BASICCONSIDERATIONS

1.2.1 GENERALAllbuildingsandstructuresshallbedesignedandconstructed inconformancewiththeprovisionsofthissection.ThebuildingsandportionsthereofshallsupportallloadsincludingdeadloadspecifiedinthischapterandelsewhereinthisCode.Impact,fatigueandselfstrainingforcesshallbeconsideredwheretheseforcesoccur.

1.2.2 BUILDINGSANDSTRUCTURESA structure shall ordinarily be described as an assemblage of framingmembers and components arranged tosupport both gravity and lateral forces. Structures may be classified as building and nonbuilding structures.Structuresthatencloseaspaceandareusedforvariousoccupanciesshallbecalledbuildingsorbuildingstructures.Structuresotherthanbuildings,suchaswatertanks,bridges,communicationtowers,chimneysetc.,shallbecalled

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nonbuildingstructures.Whenusedinconjunctionwiththewordbuilding(s),thewordstructure(s)shallmeannonbuildingstructures,e.g. 'buildingsandstructures'or 'buildingsorstructures'.Otherwisetheword 'structures'shallincludebothbuildingsandnonbuildingstructures.

1.2.3 BUILDINGANDSTRUCTUREOCCUPANCYCATEGORIESBuildingsandotherstructuresshallbeclassified,basedonthenatureofoccupancy,accordingtoTable1.2.1forthepurposesofapplying flood, surge,windandearthquakeprovisions.Theoccupancycategories range from I to IV,whereOccupancyCategoryIrepresentsbuildingsandotherstructureswithalowhazardtohumanlifeintheeventof failure and Occupancy Category IV represents essential facilities. Each building or other structure shall beassignedtothehighestapplicableoccupancycategoryorcategories.Assignmentofthesamestructuretomultipleoccupancycategoriesbasedonuseandthetypeof loadconditionbeingevaluated(e.g.,windorseismic)shallbepermissible.

Whenbuildingsorotherstructureshavemultipleuses(occupancies),therelationshipbetweentheusesofvariouspartsofthebuildingorotherstructureandtheindependenceofthestructuralsystemsforthosevariouspartsshallbeexamined.Theclassificationforeachindependentstructuralsystemofamultipleusebuildingorotherstructureshallbethatofthehighestusagegroupinanypartofthebuildingorotherstructurethatisdependentonthatbasicstructuralsystem.

1.2.4 SAFETYBuildings, structuresand components thereof, shallbedesignedand constructed to support all loads, includingdeadloads,withoutexceedingtheallowablestressesorspecifiedstrengths(underapplicablefactoredloads)forthematerialsofconstructioninthestructuralmembersandconnections.

1.2.5 SERVICEABILITYStructuralframingsystemsandcomponentsshallbedesignedwithadequatestiffnesstohavedeflections,vibration,or any other deformationswithin the serviceability limit of building or structure. The deflections of structuralmembers shall not exceed themore restrictive of the limitations provided in Chapters 2 through 13 or thatpermittedbyTable1.2.2orthenotesthat follow.Forwindandearthquake loading,storydriftandswayshallbelimitedinaccordancewiththeprovisionsofSec1.5.6.

1.2.6 RATIONALITYStructuralsystemsandcomponentsthereofshallbeanalyzed,designedandconstructedbasedonrationalmethodswhichshallinclude,butnotbelimitedto,theprovisionsofSec1.2.7

1.2.7 ANALYSISAnalysisof the structural systems shallbemade fordetermining the load effectson the resistingelements andconnections,basedonwellestablishedprinciplesofmechanicstakingequilibrium,geometriccompatibilityandbothshortandlongtermpropertiesoftheconstructionmaterialsintoaccountandincorporatingthefollowing:

1.2.7.1 MATHEMATICALMODELAmathematicalmodel of the physical structure shall represent the spatial distribution of stiffness and otherpropertiesofthestructurewhichisadequatetoprovideacompleteloadpathcapableoftransferringallloadsandforces from their points of origin to the loadresisting elements for obtaining various load effects. For dynamicanalysis,mathematicalmodelshallalso incorporatetheappropriatelydistributedmassanddampingpropertiesof

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thestructureadequateforthedeterminationofthesignificantfeaturesof itsdynamicresponse.Allbuildingsandstructures shallbe thusananlyzedpreferablyusinga threedimensionalcomputerizedmodel incorporating thesefeaturesofmathematicalmodel.It isessentialtousethreedimensionalcomputermodeltorepresentastructurehavingirregularplanconfigurationsuchasthoselistedinTables1.3.2and1.3.3andhavingrigidorsemirigidfloorand roof diaphragms. Requirements for twodimensionalmodel and three dimensionalmodels for earthquakeanalysisaredescribedinSec.2.5.11to2.5.14.Table1.2.1 OccupancyCategoryofBuildingsandOtherStructuresforFlood,Surge,WindandEarthquakeLoads

NatureofOccupancy

OccupancyCategory

Buildingsandotherstructuresthatrepresentalowhazardtohumanlifeintheeventoffailure,including,butnotlimitedto: Agriculturalfacilities Certaintemporaryfacilities Minorstoragefacilities

I

AllbuildingsandotherstructuresexceptthoselistedinOccupancyCategoriesI,III,andIV II

Buildingsandotherstructuresthatrepresentasubstantialhazardtohumanlifeintheeventoffailure,including,butnotlimitedto: Buildingsandotherstructureswheremorethan300peoplecongregateinonearea Buildingsandotherstructureswithdaycarefacilitieswithacapacitygreaterthan150 Buildingsandotherstructureswithelementaryschoolorsecondaryschoolfacilitieswithacapacitygreaterthan250 Buildingsandotherstructureswithacapacitygreaterthan500forcollegesoradulteducationfacilities Healthcarefacilitieswithacapacityof50ormoreresidentpatients,butnothavingsurgeryoremergency

treatmentfacilities Jailsanddetentionfacilities

Buildingsandotherstructures,notincludedinOccupancyCategoryIV,withpotentialtocauseasubstantialeconomicimpactand/ormassdisruptionofdaytodaycivilianlifeintheeventoffailure,including,butnotlimitedto: Powergeneratingstationsa Watertreatmentfacilities Sewagetreatmentfacilities Telecommunicationcenters

BuildingsandotherstructuresnotincludedinOccupancyCategoryIV(including,butnotlimitedto,facilitiesthatmanufacture,process,handle,store,use,ordisposeofsuchsubstancesashazardousfuels,hazardouschemicals,hazardouswaste,orexplosives)containingsufficientquantitiesoftoxicorexplosivesubstancestobedangeroustothepublicifreleased.

III

Buildingsandotherstructuresdesignatedasessentialfacilities,including,butnotlimitedto: Hospitalsandotherhealthcarefacilitieshavingsurgeryoremergencytreatmentfacilities Fire,rescue,ambulance,andpolicestationsandemergencyvehiclegarages Designatedearthquake,hurricane,orotheremergencyshelters Designatedemergencypreparedness,communication,andoperationcentersandotherfacilitiesrequiredfor

emergencyresponse Powergeneratingstationsandotherpublicutilityfacilitiesrequiredinanemergency Ancillarystructures(including,butnotlimitedto,communicationtowers,fuelstoragetanks,coolingtowers,

electricalsubstation structures,firewaterstoragetanksorotherstructureshousingorsupportingwater,orotherfiresuppressionmaterialorequipment) requiredforoperationofOccupancyCategoryIVstructuresduringanemergency

Aviationcontroltowers,airtrafficcontrolcenters,andemergencyaircrafthangars Waterstoragefacilitiesandpumpstructuresrequiredtomaintainwaterpressureforfiresuppression Buildingsandotherstructureshavingcriticalnationaldefensefunctions

Buildingsandotherstructures(including,butnotlimitedto,facilitiesthatmanufacture,process,handle,store,use,ordisposeof such substancesas hazardous fuels,hazardous chemicals,or hazardouswaste) containinghighly toxicsubstanceswhere the quantityof thematerial exceeds a thresholdquantity establishedby the authorityhavingjurisdiction.

IV

aCogenerationpowerplantsthatdonotsupplypoweronthenationalgridshallbedesignatedOccupancyCategoryII.

1.2.7.2 LOADSANDFORCESAllprescribed loadsandforcestobesupportedbythestructuralsystemsshallbedetermined inaccordancewiththeapplicableprovisionsofthischapterandChapter2.LoadsshallbeappliedonthemathematicalmodelspecifiedinSec.1.2.7.1atappropriatespatiallocationsandalongdesireddirections.

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Table1.2.2DeflectionLimits(Exceptearthquakeload)

Intheabovetable lstandsforspanof thememberunderconsideration;Lstands for live load,W stands forwindloadandDstandsfordeadload.

Notes:

a. For structural roofing and sidingmade of formedmetal sheets, the total load deflection shall not exceed l/60. For secondary roofstructural members supporting formed metal roofing, the live load deflection shall not exceed l/150. For secondary wall memberssupporting formedmetal siding, thedesignwind loaddeflection shallnot exceed l/90.For roofs, this exceptiononly applieswhen themetalsheetshavenoroofcovering.

b. Interiorpartitionsnotexceeding2minheightand flexible, foldingandportablepartitionsarenotgovernedbytheprovisionsofthissection.

c.Forcantilevermembers,lshallbetakenastwicethelengthofthecantilever.

d.Forwoodstructuralmembershavingamoisturecontentoflessthan16percentattimeofinstallationandusedunderdryconditions,thedeflectionresultingfromL+0.5DispermittedtobesubstitutedforthedeflectionresultingfromL+D.

e.Theabovedeflectionsdonotensureagainstponding.Roofsthatdonothavesufficientslopeorcambertoassureadequatedrainageshallbeinvestigatedforponding.SeeSection1.6.5forrainandpondingrequirements.

f.Thewindloadispermittedtobetakenas0.7timesthecomponentandcladdingloadsforthepurposeofdeterminingdeflectionlimitsherein.

g.Forsteelstructuralmembers,thedeadloadshallbetakenaszero.

h. For aluminum structural members or aluminum panels used in skylights and sloped glazing framing, roofs or walls of sunroomadditionsorpatiocovers,notsupportingedgeofglassoraluminumsandwichpanels,thetotalloaddeflectionshallnotexceed l/60.Forcontinuousaluminumstructuralmemberssupportingedgeofglass,thetotalloaddeflectionshallnotexceed l/175foreachglassliteorl/60fortheentirelengthofthemember,whicheverismorestringent.Foraluminumsandwichpanelsusedinroofsorwallsofsunroomadditionsorpatiocovers,thetotalloaddeflectionshallnotexceedl/120.

1.2.7.3 SOILSTRUCTUREINTERACTIONSoilstructure interactioneffects,where required, shallbe included in theanalysisbyappropriately including theproperlysubstantiatedpropertiesofsoilintothemathematicalmodelspecifiedinSec.1.2.7.1above.

1.2.8 DISTRIBUTIONOFHORIZONTALSHEARThetotallateralforceshallbedistributedtothevariouselementsofthelateralforceresistingsysteminproportiontotheirrigiditiesconsideringtherigidityofthehorizontalbracingsystemsordiaphragms.

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1.2.9 HORIZONTALTORSIONALMOMENTSStructural systems and components shall bedesigned to sustain additional forces resulting from torsiondue toeccentricitybetween thecentreofapplicationof the lateral forcesand thecentreof rigidityof the lateral forceresisting system.Forces shallnotbedecreaseddue to torsionaleffects.Foraccidental torsioneffectson seismicforces,requirementsshallconformtoSec2.5.9.6

1.2.10 STABILITYAGAINSTOVERTURNINGANDSLIDINGEverybuildingorstructureshallbedesignedtoresisttheoverturningandslidingeffectscausedbythelateralforcesspecifiedinthischapter.

1.2.11 ANCHORAGEAnchorageoftherooftowallandcolumns,andofwallsandcolumnstofoundations,shallbeprovidedtoresisttheupliftandslidingforcesresultingfromtheapplicationoftheprescribedloads.AdditionalrequirementsformasonryorconcretewallsshallbethosegiveninSec1.7.3.6.

1.2.12 GENERALSTRUCTURALINTEGRITYBuildingsandstructuralsystemsshallpossessgeneralstructuralintegrity,thatistheabilitytosustainlocaldamagecaused due tomisuse or accidental overloading,with the structure as awhole remaining stable and not beingdamagedtoanextentdisproportionatetotheoriginallocaldamage.

1.2.13 PROPORTIONINGOFSTRUCTURALELEMENTSStructuralelements,componentsandconnectionsshallbeproportionedanddetailedbasedonthedesignmethodsprovided inthesubsequentchapters forvariousmaterialsofconstruction,suchas reinforcedconcrete,masonry,steeletc.toresistvariousloadeffectsobtainedfromarationalanalysisofthestructuralsystem.

1.2.14 WALLSANDFRAMINGWalls and structural framing shall be erected true and plumb in accordance with the design. Interior walls,permanentpartitionsand temporarypartitionsexceeding1.8mofheight shallbedesigned to resistall loads towhichtheyaresubjected.IfnototherwisespecifiedelsewhereinthisCode,wallsshallbedesignedforaminimumloadof0.25kN/m2appliedperpendicular to thewall surfaces.Thedeflectionof suchwallsundera loadof0.25kN/m2shallnotexceed1/240ofthespanforwallswithbrittlefinishesand

1/120ofthespanforwallswithflexiblefinishes. However, flexible, folding or portable partitions shall not be required to meet the above load anddeflectioncriteria,butshallbeanchoredtothesupportingstructure.

1.2.15 ADDITIONSTOEXISTINGSTRUCTURESWhenanexistingbuildingorstructureisextendedorotherwisealtered,allportionsthereofaffectedbysuchcauseshallbestrengthened,ifnecessary,tocomplywiththesafetyandserviceabilityrequirementsprovidedinSec1.2.4and1.2.5respectively.

1.2.16 PHASEDCONSTRUCTIONWhenabuildingorstructureisplannedoranticipatedtoundergophasedconstruction,structuralmembersthereinshallbeinvestigatedanddesignedforanyadditionalstressesarisingduetosuchconstruction.

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1.2.17 LOADCOMBINATIONSANDSTRESSINCREASEEvery building, structure, foundation or components thereof shall be designed to sustain,within the allowablestress or specified strength (under factored load), the most unfavourable effects resulting from variouscombinationsofloadsspecifiedinsection2.7.ExceptotherwisepermittedorrestrictedbyanyothersectionofthisCode,maximumincreaseintheallowablestressshallbe33%whenallowableorworkingstressmethodofdesignisfollowed.Forsoilstressesduetofoundationloads,loadcombinationsandstressincreasespecifiedinSec2.7.4forallowablestressdesignmethodshallbeused.

1.3 STRUCTURALSYSTEMS

1.3.1 GENERALEverystructureshallhaveoneofthebasicstructuralsystemsspecified inSec1.3.2oracombinationthereof.ThestructuralconfigurationshallbeasspecifiedinSec1.3.4withthelimitationsimposedinSec2.5.7.4.

1.3.2 BASICSTRUCTURALSYSTEMSStructuralsystemsforbuildingsandotherstructuresshallbedesignatedasoneofthetypesAtoGlisted inTable1.3.1.Each type isagain classifiedas shown in the tableby the typesof verticalelementsused to resist lateralforces.Abriefdescriptionofdifferentstructuralsystemsarepresentedinfollowingsubsections.

Table1.3.1:BasicStructuralSystemsA.BEARINGWALLSYSTEMS(noframe)

1. Special reinforced concrete shear walls 2. Ordinary reinforced concrete shear walls 3. Ordinary reinforced masonry shear walls 4. Ordinary plain masonry shear walls

B.BUILDINGFRAMESYSTEMS(withbracingorshearwall)1. Steel eccentrically braced frames, moment resisting connections at columns away from links2. Steel eccentrically braced frames, non-moment-resisting, connections at columns away from links3. Special steel concentrically braced frames4. Ordinary steel concentrically braced frames5. Special reinforced concrete shear walls 6. Ordinary reinforced concrete shear walls 7. Ordinary reinforced masonry shear walls 8. Ordinary plain masonry shear walls

C.MOMENTRESISTINGFRAMESYSTEMS(noshearwall) 1. Special steel moment frames2. Intermediate steel moment frames3. Ordinary steel moment frames4. Special reinforced concrete moment frames 5. Intermediate reinforced concrete moment frames 6. Ordinary reinforced concrete moment frames

D.DUALSYSTEMS:SPECIALMOMENTFRAMESCAPABLEOFRESISTINGATLEAST25%OFPRESCRIBEDSEISMICFORCES(withbracingorshearwall)

1. Steel eccentrically braced frames2. Special steel concentrically braced frames 3. Special reinforced concrete shear walls4. Ordinary reinforced concrete shear walls

E.DUALSYSTEMS:INTERMEDIATEMOMENTFRAMESCAPABLEOFRESISTINGATLEAST25%OFPRESCRIBEDSEISMICFORCES(withbracingorshearwall)

1. Special steel concentrically braced frames 2. Special reinforced concrete shear walls3. Ordinary reinforced masonry shear walls 4. Ordinary reinforced concrete shear walls

F.DUALSHEARWALLFRAMESYSTEM:ORDINARYREINFORCEDCONCRETEMOMENTFRAMESANDORDINARYREINFORCEDCONCRETESHEARWALLS G.STEELSYSTEMSNOTSPECIFICALLYDETAILEDFORSEISMICRESISTANCE

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1.3.2.1 BEARINGWALLSYSTEMA structural systemhaving bearingwalls orbracing systemswithout a complete vertical load carrying frame tosupportgravityloads.Resistancetolateralloadsisprovidedbyshearwallsorbracedframes.

1.3.2.2 BUILDINGFRAMESYSTEMA structural systemwith an essentially complete space frameproviding support for gravity loads.Resistance tolateralloadsisprovidedbyshearwallsorbracedframesseparately.

1.3.2.3 MOMENTRESISTINGFRAMESYSTEMAstructuralsystemwithanessentiallycompletespaceframeprovidingsupportforgravityloads.Momentresistingframesalsoprovideresistancetolateralloadprimarilybyflexuralactionofmembers,andmaybeclassifiedasoneofthefollowingtypes:

a) SpecialMomentResistingFrames(SMRF)

b) IntermediateMomentResistingFrames(IMRF)

c) OrdinaryMomentResistingFrames(OMRF).

The framing system, IMRFandSMRF shallhave specialdetailing toprovideductilebehaviour conforming to theprovisionsofSec8.3and10.20 forconcreteand steel structures respectively.OMRFneednotconform to thesespecialductilityrequirementsofChapter8or10.

1.3.2.4 DUALSYSTEMAstructuralsystemhavingacombinationofthefollowingframingsystems:

a) Momentresistingframes(SMRF,IMRForsteelOMRF),and

b) Shearwallsorbracedframes.

Thetwosystemsspecifiedin(a)and(b)aboveshallbedesignedtoresistthetotallateralforceinproportiontotheirrelativerigiditiesconsideringtheinteractionofthedualsystematalllevels.However,themomentresistingframesshallbecapableofresistingatleast25%oftheapplicabletotalseismiclateralforce,evenwhenwindoranyotherlateralforcegovernsthedesign.

1.3.2.5 SPECIALSTRUCTURALSYSTEM:AstructuralsystemnotdefinedabovenorlistedinTable1.3.1andspeciallydesignedtocarrythelateralloads,suchastubeintube,bundledtube,etc.

1.3.2.6 NONBUILDINGSTRUCTURALSYSTEMAstructuralsystemusedforpurposesotherthaninbuildingsandconformingtoSec1.5.4.8,1.5.4.9,2.4and2.5.

1.3.3 COMBINATIONOFSTRUCTURALSYSTEMSWhendifferentstructuralsystemsofSec1.3.2arecombined for incorporation intothesamestructure,designofthecombinedseismicforceresistingsystemshallconformtotheprovisionsofSec2.5.7.5.

1.3.4 STRUCTURALCONFIGURATIONSBased on the structural configuration, each structure shall be designated as a regular or irregular structure asdefinedbelow:

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1.3.4.1 REGULARSTRUCTURESRegularstructureshavenosignificantphysicaldiscontinuitiesorirregularitiesinplanorverticalconfigurationorintheirlateralforceresistingsystems.TypicalfeaturescausingirregularityaredescribedinSec1.3.4.2.

1.3.4.2 IRREGULARSTRUCTURESIrregularstructureshaveeithervertical irregularityorplan irregularityorboth intheirstructuralconfigurationsorlateralforceresistingsystems.

1.3.4.2.1 VerticalIrregularity

StructureshavingoneormoreoftheirregularfeatureslistedinTable1.3.2shallbedesignatedashavingaverticalirregularity.

Table1.3.2:VerticalIrregularitiesofStructures

VerticalIrregularity Reference*Type Definition SectionI StiffnessIrregularity(SoftStorey):

Asoftstoreyisoneinwhichthelateralstiffnessislessthan70percentofthatin the storey above or less than 80 per cent of the average stiffness of thethreestoreysabove.

2.5.7to2.5.14and2.5.19

II MassIrregularity:Massirregularityshallbeconsideredtoexistwheretheeffectivemassofanystoreyismorethan150percentoftheeffectivemassofanadjacentstorey.Aroofwhichislighterthanthefloorbelowneednotbeconsidered.

2.5.7to2.5.14

III VerticalGeometricIrregularity:Verticalgeometricirregularityshallbeconsideredtoexistwherehorizontaldimensionofthelateralforceresistingsysteminanystoreyismorethan130per cent of that in an adjacent storey, onestorey penthouses need not beconsidered.

2.5.7to2.5.14

IV InPlaneDiscontinuityinVerticalLateralForceResistingElement:An inplane offset of the lateral loadresisting elements greater than thelengthofthoseelements.

2.5.7to2.5.14

Va DiscontinuityinCapacity(WeakStorey):Aweakstoreyisoneinwhichthestoreystrengthislessthan80percentofthat in the storey above. The storey strength is the total strength of allseismicresisting elements sharing the storey shear for the direction underconsideration.

2.5.7to2.5.14and2.5.19

Vb ExtremeDiscontinuityinCapacity(VeryWeakStorey):Averyweakstoreyisoneinwhichthestoreystrengthislessthan65percentofthatinthestoreyabove.

2.5.7to2.5.14and2.5.19

1.3.4.2.2 PlanIrregularity

Structureshavingoneormoreof the irregular features listed inTable1.3.3shallbedesignatedashavingaplanirregularity.

Table1.3.3:PlanIrregularitiesofStructures

PlanIrregularity Reference*Type Definition SectionI Torsional Irregularity (to be considered when diaphragms are not

flexible):Torsional irregularity shall be considered to existwhen themaximumstoreydrift,computedincludingaccidentaltorsion,atoneendofthestructureismorethan1.2timestheaverageofthestoreydriftsatthetwoendsofthestructure.

2.5.7to2.5.14

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II ReentrantCorners:Planconfigurationsofastructureanditslateralforceresistingsystemcontainreentrantcorners,wherebothprojectionsofthestructurebeyondareentrantcorneraregreater than15percentof theplandimensionof thestructure inthegivendirection.

2.5.7to2.5.14

III DiaphragmDiscontinuity:Diaphragms with abrupt discontinuities or variations in stiffness, includingthose having cutout or open areas greater than 50 per cent of the grossenclosedareaofthediaphragm,orchangesineffectivediaphragmstiffnessofmorethan50percentfromonestoreytothenext.

2.5.7to2.5.14

IV OutofplaneOffsets:Discontinuities in a lateral force path, such as outofplane offsets of theverticalelements.

2.5.7to2.5.14

V NonparallelSystems:The vertical lateral loadresisting elements are not parallel to or symmetricaboutthemajororthogonalaxesofthelateralforceresistingsystem.

2.5.7to2.5.14

1.4 DESIGNFORGRAVITYLOADS

1.4.1 GENERALDesignofbuildingsand components thereof forgravity loads shall conform to the requirementsof this section.Gravity loads, suchasdead loadand live loadsappliedat the floorsor roofofabuilding shallbedetermined inaccordancewiththeprovisionsofChapter2.

1.4.2 FLOORDESIGNFloorslabsanddecksshallbedesignedforthefulldeadandliveloadsasspecified inSec2.2and2.3respectively.Floor supporting elements such as beams, joists, columns etc. shall be designed for the full dead load and theappropriately reduced live loads set forth by the provisions of Sec 2.3.13. Design of floor elements shall alsoconformtothefollowingprovisions:

a) UniformlyDistributedLoads:Whereuniformfloorloadsareinvolved,considerationmaybelimitedtofulldeadloadonallspansincombinationwithfullliveloadonadjacentspansandon alternate spans to determine themost unfavourable effect of stresses in thememberconcerned.

b) ConcentratedLoads : Provisionshallbemade indesigning floors foraconcentrated loadasset forth in Sec 2.3.5 applied at a location wherever this load acting upon an otherwiseunloaded floor would produce stresses greater than those caused by the uniform loadrequiredtherefore.

c) PartitionLoads :Loadsdue topermanentpartitions shallbe treatedasadead loadappliedoverthefloorasauniformlineloadhavinganintensityequaltotheweightpermetrerunofthepartitionsasspecifiedinSec2.2.5.LoadsforlightmovablepartitionsshallbedeterminedinaccordancewiththeprovisionsofSec2.3.6.

d) Design ofMembers : Floormembers, such as slabs or decks, beams, joists etc. shall bedesignedtosustaintheworsteffectofthedeadplusliveloadsoranyotherloadcombinationsasspecifiedinSec2.7.Wherefloorsareusedasdiaphragmstotransmitlateralloadsbetweenvarious resisting elements, those loads shall be determined following the provisions of Sec1.7.3.8. Detailed design of the floor elements shall be performed using the proceduresprovidedinChapters4through13forvariousconstructionmaterials.

Part6

12

1.4.3 ROOFDESIGNRoofs and their supporting elements shall be designed to sustain, within their allowable stresses or specifiedstrength limits,alldead loadsand live loadsassetoutbytheprovisionsofSec2.2and2.3respectively.Designofroofmembersshallalsoconformtothefollowingrequirements:

a) Application of Loads :When uniformly distributed loads are considered for the design ofcontinuousstructuralmembers,loadincludingfulldeadloadsonallspansincombinationwithfullliveloadsonadjacentspansandonalternatespan,shallbeinvestigatedtodeterminetheworst effects of loading. Concentrated roof live loads and special roof live loads, whereapplicable,shallalsobeconsideredindesign.

b) UnbalancedLoading:Effectsduetounbalancedloadsshallbeconsideredinthedesignofroofmembersandconnectionswheresuchloadingwillresultinmorecriticalstresses.Trussesandarchesshallbedesignedtoresistthestressescausedbyuniformliveloadsononehalfofthespan if such loading results in reverse stresses, or stresses greater in any portion than thestressesproducedbythisunitliveloadwhenappliedupontheentirespan.

c) RainLoads:Roofs,wherepondingofrainwaterisanticipatedduetoblockageofroofdrains,excessivedeflectionor insufficientslopes,shallbedesignedtosupportsuch loads.Loadsonroofs due to rain shall be determined in accordance with the provisions of Sec 2.6.3. Inadditiontothedeadloadoftheroof,eithertheroofliveloadortherainload,whicheverisofhigherintensity,shallbeconsideredindesign.

1.4.4 REDUCTIONOFLIVELOADSThedesign live loadsspecified inSec2.3,maybereducedtoappropriatevaluesaspermittedbytheprovisionsofSec2.3.13.andSec.2.3.14.

1.4.5 POSTINGOFLIVELOADSIneverybuilding,ofwhichthefloorsorpartsthereofhaveadesignliveloadof3.5kN/m2ormore,andwhichareused as library stack room, file room, parking garage,machineorplant room,or used for industrialor storagepurposes,theownerofthebuildingshallensurethatthe live loads forwhichsuchspacehasbeendesigned,arepostedondurablemetalplatesasshowninFig1.1,securelyaffixedinaconspicuousplaceineachspacetowhichtheyrelate.Ifsuchplatesarelost,removed,ordefaced,theownershallberesponsibletohavethemreplaced.

1.4.6 RESTRICTIONSONLOADINGThebuildingowner shallensure that the live load forwhicha flooror roof isorhasbeendesigned,willnotbeexceededduringitsuse.

1.4.7 SPECIALCONSIDERATIONSIntheabsenceofactualdeadandliveloaddata,theminimumvaluesoftheseloadsshallbethosespecifiedinSec2.2and2.3.Inaddition,specialconsiderationshallbegiventothefollowingaspectsofloadinganddueallowancesshallbemadeindesignifoccurrenceofsuchloadingisanticipatedafterconstructionofabuilding:

a) IncreaseinDeadLoad:Actualthicknessoftheconcreteslabsorothermembersmaybecomelargerthanthedesignedthicknessduetomovementsordeflectionsofthe formworkduringconstruction.

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Part6

14

1.5.3.1 DIRECTIONOFWINDStructural design for wind forces shall be based on the assumption that windmay blow from any horizontaldirection.

1.5.3.2 DESIGNCONSIDERATIONSDesignwindloadontheprimaryframingsystemsandcomponentsofabuildingorstructureshallbedeterminedonthebasisoftheproceduresprovidedinSec2.4consideringthebasicwindspeed,shapeandsizeofthebuilding,andtheterrainexposureconditionofthesite.Forslenderbuildingsandstructures,dynamicresponsecharacteristics,such as fundamental natural frequency, shall be determined for calculating the gust response coefficient. Loadeffects, such as forces,moments, deflections etc. on various components of the building due towind shall bedeterminedfromastaticanalysisofthestructureasspecifiedinSec1.2.7.1.

1.5.3.3 SHIELDINGEFFECTReductions inwindpressureonbuildingsand structuresdue toapparentdirect shieldingeffectsof theupwindobstructions,suchasmanmadeconstructionsornaturalterrainfeatures,shallnotbepermitted.

1.5.3.4 DYNAMICEFFECTSDynamicwind forces suchas that fromalongwind vibrations causedby thedynamicwindstructure interactioneffects,as set forthby theprovisionsofSec2.4.10, shallbe considered in thedesignof regular shaped slenderbuildings.Forotherdynamiceffectssuchascrosswindortorsionalresponsesasmaybeexperiencedbybuildingsorstructureshavingunusualgeometricalshapes(i.e.verticalorplan irregularitieslistedinTables1.3.2and1.3.3),responsecharacteristics,orsitelocations,structuraldesignshallbemadebasedontheinformationobtainedeitherfromother reliable referencesor fromwindtunnel testspecified inSec1.5.3.5below,complyingwith theotherrequirementsofthissection.

1.5.3.5 WINDTUNNELTESTProperlyconductedwindtunneltestsshallberequiredforthosebuildingsorstructureshavingunusualgeometricshapes,responsecharacteristics,orsitelocationsforwhichcrosswindresponsesuchasvortexshedding,gallopingetc.warrant special consideration, and forwhich no reliable literature for the determination of such effects isavailable.This test isalso recommended for thosebuildingsor structures forwhichmoreaccuratewindloadinginformationisdesiredthanthosegiveninthissectionandinSec2.4.

Testsforthedeterminationofmeanandfluctuatingcomponentsofforcesandpressuresshallbeconsideredtobeproperlyconductedonlyifthefollowingrequirementsaresatisfied:

a) Thenaturalwindhasbeenmodelledtoaccountforthevariationofwindspeedwithheight,

b) The intensityof the longitudinalcomponentsof turbulencehasbeen taken intoconsideration in themodel,

c) Thegeometricscaleof thestructuralmodel isnotmore than three times thegeometricscaleof thelongitudinalcomponentofturbulence,

d) Theresponsecharacteristicsofthewindtunnelinstrumentationareconsistentwiththemeasurementstobemade,and

e) The Reynolds number is taken into consideration when determining forces and pressures on thestructuralelements.

Chapter1

15

Tests for the purpose of determining the dynamic response of a structure shall be considered to be properlyconductedonly if requirements (a) through (e)aboveare fulfilledand, inaddition, thestructuralmodel isscaledwithdueconsiderationtolength,distributionofmass,stiffnessanddampingofthestructure.

1.5.3.6 WINDLOADSDURINGCONSTRUCTIONBuildings, structures and portions thereof under construction, and construction structures such as formwork,stagingetc.shallbeprovidedwithadequatetemporarybracingsorotherlateralsupportstoresistthewindloadonthemduringtheerectionandconstructionphase.

1.5.3.7 MASONRYCONSTRUCTIONINHIGHWINDREGIONSDesignandconstructionofmasonrystructuresinhighwindregionsshallconformtotherequirementsofrelevantsectionsofChapter7.

1.5.3.8 HEIGHTLIMITSUnlessotherwisespecifiedelsewhereinthisCode,noheightlimitsshallbeimposed,ingeneral,onthedesignandconstructionofbuildingsorstructurestoresistwindinducedforces.

1.5.4 DESIGNFOREARTHQUAKEFORCESDesign of structures and components thereof to resist the effects of earthquake forces shall complywith therequirementsofthissection.

1.5.4.1 BASICDESIGNCONSIDERATIONForthepurposeofearthquakeresistantdesign,eachstructureshallbeplacedinoneoftheseismiczonesasgiveninSec2.5.6.2andassignedwitha structure importance categoryas set forth inSec2.5.7.1.The seismic forcesonstructuresshallbedeterminedconsideringseismiczoning,sitesoilcharacteristics,structureimportance,structuralsystemsandconfigurations,heightanddynamicpropertiesofthestructureasprovided inSec2.5.ThestructuralsystemandconfigurationtypesforabuildingorastructureshallbedeterminedinaccordancewiththeprovisionsofSec2.5.7.4.Otherseismicdesignrequirementsshallbethosespecifiedinthissection.

1.5.4.2 REQUIREMENTSFORDIRECTIONALEFFECTSThedirectionsofapplicationofseismicforcesusedinthedesignshallbethosewhichwillproducethemostcriticalloadeffects.Earthquakeforcesactinbothprincipaldirectionsofthebuildingsimultaneously.DesignprovisionsforconsideringearthquakecomponentinorthogonaldirectionshavebeenprovidedinSec2.5.15.1.

1.5.4.3 STRUCTURALSYSTEMANDCONFIGURATIONREQUIREMENTSSeismicdesignprovisionsimposethefollowinglimitationsontheuseofstructuralsystemsandconfigurations:

a) The structural systemused shall satisfy requirementsof theSeismicDesignCategory (defined inSec.2.5.7.2)andheightlimitationsgiveninSec2.5.7.4.

b) StructuresassignedtoSeismicDesignCategoryDhavingverticalirregularityTypeVbofTable1.3.2shall not be permitted. Structureswith such vertical irregularitymay be permitted for SeismicDesignCategoryBorCbutshallnotbeovertwostoriesor9minheight.

c) Structures having irregular features described in Table 1.3.2 or 1.3.3 shall be designed incompliancewiththeadditionalrequirementsofthesectionsreferencedintheseTables.

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16

d) SpecialStructuralSystemsdefined inSec1.3.2.5maybepermitted if itcanbedemonstratedbyanalytical and test data to be equivalent, with regard to dynamic characteristics, lateral forceresistance and energy absorption, to one of the structural systems listed in Table 2.5.7, forobtaininganequivalentRandCdvalueforseismicdesign.

1.5.4.4 METHODSOFANALYSISEarthquake forces and their effects on various structural elements shall be determined by using either a staticanalysismethodoradynamicanalysismethodwhicheverisapplicablebasedonthelimitationssetforthinSec2.5.7through2.5.14andconformingtoSec1.2.7.

1.5.4.5 MINIMUMDESIGNSEISMICFORCETheminimumdesign seismic forces shall be thosedetermined in accordancewith the Sec 2.5.7 through 2.5.14whicheverisapplicable.

1.5.4.6 DISTRIBUTIONOFSEISMICFORCESThetotallateralseismicforcesandmomentsshallbedistributedamongvariousresistingelementsatanylevelandalongtheverticaldirectionofabuildingorstructureinaccordancewiththeprovisionsofSec2.5.7through2.5.14asappropriate.

1.5.4.7 VERTICALCOMPONENTSOFSEISMICFORCESDesignprovisionsforconsideringverticalcomponentofearthquakegroundmotionisgiveninSec2.5.15.2

1.5.4.8 HEIGHTLIMITSHeightlimitationsfordifferentstructuralsystemsaregiveninTable2.5.7ofSec2.5.7.4ofPart6ofthiscodeasafunctionofseismicdesigncategory.

1.5.4.9 NONBUILDINGSTRUCTURESSeismiclateralforceonnonbuildingstructuresshallbedeterminedinaccordancewiththeprovisionsofChapter15ofASCE705.However,provisionsofChapter15ofASCE705maybesimplified,consistentwiththeprovisionsofSection2.5ofPart6ofthiscode.Otherdesignrequirementsshallbethoseprovidedinthischapter.

1.5.5 OVERTURNINGREQUIREMENTSEverystructureshallbedesignedtoresisttheoverturningeffectscausedbywindorearthquakeforcesspecifiedinSec2.4and2.5respectivelyaswellotherlateralforceslikeearthpressure,tidalsurgeetc.TheoverturningmomentMxatanystoreylevelxofabuildingshallbedeterminedas:

1.5.1

where,

hi,hx,hn = Heightinmetresatleveli,xornrespectively.

Fi = Lateralforceappliedatleveli,i=1ton.

Chapter1

17

Atanylevel,theincrementofoverturningmomentshallbedistributedtothevariousresistingelementsinthesamemannerasthedistributionofhorizontalshearprescribedinSec2.5.9.5.Overturningeffectsoneveryelementshallbecarrieddowntothefoundationlevel.

1.5.6 DRIFTANDBUILDINGSEPARATION

1.5.6.1 STOREYDRIFTLIMITATIONStoreydriftisthehorizontaldisplacementofonelevelofabuildingorstructurerelativetothelevelaboveorbelowduetothedesigngravity(deadandliveloads)orlateralforces(e.g.windandearthquakeloads).Exceptotherwisepermitted in Sec 1.3.4.2.1 calculated storey drift shall include both translational and torsional deflections andconformtothefollowingrequirements:

1. Storeydrift,,forloadsotherthanearthquakeloads,shallbelimitedasfollows:

0.005h forT

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18

1.6 DESIGNFORMISCELLANEOUSLOADS

1.6.1 GENERALBuildings,structuresandcomponents thereof,whensubject to loadsother thandead, live,windandearthquakeloads,shallbedesignedinaccordancewiththeprovisionsofthissection.Miscellaneousloads,suchasthoseduetotemperature,rain,floodandsurgeetc.onbuildingsorstructures,shallbedeterminedinaccordancewithSec2.6.Structuralmemberssubjecttomiscellaneousloads,notspecifiedinSec2.6shallbedesignedusingwellestablishedmethodsgiveninanyreliablereferences,andcomplyingwiththeotherrequirementsofthisCode.

1.6.2 SELFSTRAININGFORCESSelfstraining forces such as those arising due to assumed differential settlements of foundations and fromrestraineddimensionalchangesduetotemperature,moisture,shrinkage,creep,andsimilareffects,shallbetakenintoconsiderationinthedesignofstructuralmembers.

1.6.3 STRESSREVERSALANDFATIGUEStructuralmembersand joints shallbe investigatedanddesignedagainstpossible stress reversalscauseddue tovariousconstruction loads.Where required,allowance shallbemade in thedesign toaccount for theeffectsoffatigue.Theallowablestressmaybeappropriatelyreducedtoaccountforsucheffectsinthestructuralmembers.

1.6.4 FLOOD,TIDAL/STORMSURGEANDTSUNAMIBuildings, structures and components thereof shall be designed, constructed and anchored to resist flotation,collapseoranypermanentmovementduetoloadsincludingflood,tidal/Stormsurgeandtsunami,whenapplicable.Structuralmembersshallbedesignedtoresistbothhydrostaticandsignificanthydrodynamic loadsandeffectsofbuoyancyresulting fromfloodorsurge.Floodandsurge loadsonbuildingsandstructuresshallbedetermined inaccordancewithSec2.6.4.Loadcombination including floodand surge loads shallconform toSec2.7.DesignoffoundationstosustaintheseloadeffectsshallconformtotheprovisionsofSec1.8.

Stability against overturning and sliding caused due towind and flood or surge loads simultaneously shall beinvestigated,andsucheffectsshallberesistedwithaminimumfactorofsafetyof1.5,consideringdeadloadonly.

1.6.5 RAINLOADSRoofsofthebuildingsandstructuresaswellastheirothercomponentswhichmayhavethecapabilityofretainingrainwatershallbedesignedforadequategravityloadinducedbyponding.RoofsandsuchothercomponentsshallbeanalysedanddesignedforloadduetopondingcausedbyaccidentalblockageofdrainagesystemcomplyingwithSec.2.6.3.

1.6.6 OTHERLOADSBuildingsandstructuresandtheircomponentsshallbeanalyzedanddesignedforstressescausedbythefollowingeffects

a. TemparatureEffects(Sec2.6.5).

b. SoilandHydrostaticPressure(Sec2.6.6).

c. ImpactsandCollisions

d. Explosions(Sec2.6.7).

Chapter1

19

e. Fire

f. VerticalForcesonAirRaidShelters(Sec2.6.8).

g. LoadsonHelicopterLandingAreas(Sec2.6.9).

h. ErectionandConstructionLoads(Sec2.6.10).

i. MovingLoadsforCraneMovements

j. CreepandShrinkage

k. DynamicLoadsduetoVibrations

l. ConstructionLoads

DesignofbuildingsandstructuresshallincludeloadingandstressescausedbytheaboveeffectsinaccordancewiththeprovisionssetforthinChapter2.

1.7 DETAILEDDESIGNREQUIREMENTS

1.7.1 GENERALAll structural framing systems shall comply with the requirements of this section. Only the elements of thedesignated lateral force resisting systems canbeused to resistdesign lateral forces specified inChapter 2.Theindividualcomponentsshallbedesignedtoresisttheprescribedforcesactingonthem.DesignofcomponentsshallalsocomplywiththespecificrequirementsforthematerialscontainedinChapters4through13.Inaddition,suchframingsystemsandcomponentsshallcomplywiththedesignrequirementsprovidedinthissection.

1.7.2 STRUCTURALFRAMINGSYSTEMSThebasicstructuralsystemsaredefinedinSec1.3.2andshowninTable1.3.1,andeachtypeissubdividedbythetypesofframingelementsusedtoresistthelateralforces.Thestructuralsystemusedshallsatisfyrequirementsofseismicdesigncategoryandheight limitations indicated inTable 2.5.7.Specialframingrequirementsaregiven inthefollowingsectionsinadditiontothoseprovidedinChapters4through13.

1.7.3 DETAILINGREQUIREMENTSFORCOMBINATIONSOFSTRUCTURALSYSTEMS:

Forcomponentscommontodifferentstructuralsystems,amorerestrictivedetailingshallbeprovided.

1.7.3.1 CONNECTIONSTORESISTSEISMICFORCESConnections which resist prescribed seismic forces shall be designed in accordance with the seismic designrequirements provided in Chapters 4 through 13.Detailed sketches for these connections shall be given in thestructuraldrawings.

1.7.3.2 DEFORMATIONCOMPATIBILITYAllframingelementsnotrequiredbydesigntobepartofthelateralforceresistingsystem,shallbeinvestigatedandshowntobeadequateforverticalloadcarryingcapacitywhensubjectedtolateraldisplacementsresultingfromtheseismic lateral forces. For designs using working stress methods, this capacity may be determined using anallowablestressincreaseof30percent.PDeltaeffectsonsuchelementsshallbeaccountedfor.

Part6

20

a. AdjoiningRigidElements : Momentresisting framesmaybeenclosedoradjoinedbymorerigidelementswhichwouldtendtopreventaspaceframefromresistinglateralforceswhereitcanbeshownthattheactionorfailureofthemorerigidelementswillnotimpairtheverticalandlateralloadresistingabilityofthespaceframe.

b. ExteriorElements :Exteriornonbearing,nonshearwallpanelsorelementswhichareattachedtoorenclosetheexteriorofastructure,shallbedesignedtoresisttheforcesaccordingtoSec.2.5.17ofChapter2, if seismic forcesarepresent,and shallaccommodatemovementsof the structureresulting from lateral forces or temperature changes. Such elements shall be supported bystructural members or by mechanical connections and fasteners joining them to structuralmembersinaccordancewiththefollowingprovisions:

i. Connectionsandpaneljointsshallallowforarelativemovementbetweenstoreysofnotlessthan two times the storeydriftcausedbywind forcesordesign seismic forces,or12mm,whicheverisgreater.

ii. Connections topermitmovement in theplaneof thepanel for storeydrift shallbe eitherslidingconnectionsusingslottedoroversizedholes,connectionswhichpermitmovementbybendingofsteel,orotherconnectionsprovidingequivalentslidingandductilitycapacity.

iii. Bodiesof connections shallhave sufficientductilityand rotation capability toprecludeanyfractureoftheanchoringelementsorbrittlefailuresatornearweldings.

iv. Bodiesof the connection shallbedesigned for1.33 times the seismic forcedeterminedbySec.2.5.17ofChapter2,orequivalent.

v. All fasteners in the connection system, such as bolts, inserts,welds, dowels etc. shall bedesignedfor4timestheforcesdeterminedbySec.2.5.17ofChapter2orequivalent.

vi. Fastenersembeddedinconcreteshallbeattachedto,orhookedaroundreinforcingsteel,orotherwiseterminatedsoastotransferforcestothereinforcingsteeleffectively.

1.7.3.3 TIESANDCONTINUITYAllpartsofastructureshallbe interconnected.Theseconnectionsshallbecapableoftransmittingtheprescribedlateralforcetothelateralforceresistingsystem.Individualmembers,includingthosenotpartoftheseismicforceresisting system, shall be provided with adequate strength to resist the shears, axial forces, and momentsdetermined inaccordancewith thisstandard.Connectionsshalldevelop thestrengthof theconnectedmembersandshallbecapableoftransmittingtheseismicforce(Fp)inducedbythepartsbeingconnected.

1.7.3.4 COLLECTORELEMENTSCollector elements shall be provided which are capable of transferring the lateral forces originating in otherportionsofthestructuretotheelementprovidingtheresistancetothoseforces.

1.7.3.5 CONCRETEFRAMESWhenconcreteframesareprovidedbydesigntobepartofthelateralforceresistingsystem,theyshallconformtothefollowingprovisions:

a) InSeismicZones3and4theseframesshallbedesignedasspecialmomentresistingframes(SMRF).

b) InSeismicZone2theyshall,asaminimum,beintermediatemomentresistingframes(IMRF).

Chapter1

21

1.7.3.6 ANCHORAGEOFCONCRETEANDMASONRYSTRUCTURALWALLSThe concrete andmasonry structuralwalls shall be anchored to supporting construction. The anchorage shallprovide a positive direct connection between thewall and floor or roof and shall be capable of resisting thehorizontal forces specified in Secs2.4.13 and2.5.17,or aminimum forceof4.09 kN/mofwall.Walls shallbedesignedtoresistbendingbetweenanchorswheretheanchorspacingexceeds1.2m.Inmasonrywallsofhollowunits or cavity walls, anchors shall be embedded in a reinforced grouted structural element of the wall.Deformationsof the floorand roofdiaphragms shallbeconsidered in thedesignof the supportedwallsand theanchorageforcesinthediaphragmsshallbedeterminedinaccordancewithSec1.7.3.9below.

1.7.3.7 BOUNDARYMEMBERSSpeciallydetailedboundarymembers shallbe considered for shearwallsand shearwallelementswhenever theirdesignisgovernedbyflexure.

1.7.3.8 FLOORANDROOFDIAPHRAGMSDeflection in the plane of thediaphragm shallnot exceed the permissibledeflection of the attached elements.Permissibledeflection shallbe thatdeflectionwhichwillpermit the attached element tomaintain its structuralintegrityundertheindividualloadingandcontinuetosupporttheprescribedloads.Designofdiaphragmsshallalsocomplywiththefollowingrequirements.

a) DiaphragmForces:DiaphragmsshallbedesignedtoresisttheseismicforcesgiveninSec2.5orforsimilarnonseismiclateralforces,whicheverisgreater.

b) DiaphragmTies:Diaphragmssupportingconcreteormasonrywallsshallhavecontinuousties,orstrutsbetween thediaphragm chords todistribute theanchorage forces specified inSec1.7.3.6above.Addedchordsmaybeprovidedtoformsubdiaphragmstotransmittheanchorageforcestothemaincrossties.

c) WoodDiaphragms :Wherewooddiaphragmsareused to laterallysupportconcreteormasonrywalls,theanchorageshallconformtoSec1.7.3.6above.InseismicZones2,3and4thefollowingrequirementsshallalsoapply:

i. Anchorageshallnotbeaccomplishedbyuseoftoenailsornailssubjecttowithdrawal,norshallwoodledgersorframingbeusedincrossgrainbendingorcrossgraintension.

ii. The continuous ties required by paragraph (b) above, shall be in addition to thediaphragmsheathing.

d) Structureshavingirregularities

i) ForstructuresassignedtoSeismicDesignCategoryDandhavingaplanirregularityofTypeI,II,III,orIVinTable1.3.3oraverticalstructuralirregularityofTypeIVinTable1.3.2,thedesignforcesdeterminedfromSection2.5.9shallbeincreased25percentforconnectionsofdiaphragms toverticalelementsand tocollectorsand forconnectionsofcollectors tothe vertical elements. Collectors and their connections also shall be designed for theseincreased forces unless they are designed for the load combinationswith overstrengthfactor.

ii) For structureshavingaplan irregularityofType II inTable1.3.3,diaphragm chords andcollectorsshallbedesignedconsideringindependentmovementofanyprojectingwingsof

Part6

22

thestructure.Eachofthesediaphragmelementsshallbedesignedforthemoresevereofthefollowingcases:

1. Motionoftheprojectingwingsinthesamedirection.

2. Motionoftheprojectingwingsinopposingdirections.

Exception:

ThisrequirementmaybedeemedtobesatisfiediftheproceduresofSec2.5.10whenseismicforcesarepresent,inconjunctionwithathreedimensionalmodel,havebeenusedtodeterminethelateralseismicforcesfordesign.

1.7.3.9 FRAMINGBELOWTHEBASEWhenstructuralframingscontinuebelowthebase,thefollowingrequirementsshallbesatisfied.

a. FramingbetweentheBaseandtheFoundation:Thestrengthandstiffnessoftheframingbetweenthebaseandthefoundationshallnotbelessthanthatofthesuperstructure.Thespecialdetailingrequirementsof Sec8.3or10.20,asappropriate for reinforced concreteor steel, shallapply tocolumns supporting discontinuous lateral force resisting elements and to SMRF, IMRF, and EBFsystemelementsbelow thebasewhichare required to transmit the forcesresulting from lateralloadstothefoundation.

b. Foundations: The foundation shall be capable of transmitting the design base shear and theoverturning forces from the superstructure into the supporting soil,but the short termdynamicnatureof the loadsmaybe taken intoaccount inestablishing the soilproperties.Sec1.8belowprescribestheadditionalrequirementsforspecifictypesoffoundationconstruction.

1.8 FOUNDATIONDESIGNREQUIREMENTS

1.8.1 GENERALThedesignandconstructionof foundation, foundationcomponentsandconnectionbetween the foundationandsuperstructureshallconformtotherequirementsofthissectionandapplicableprovisionsofChapter3andotherportionsofthisCode.

1.8.2 SOILCAPACITIESThebearingcapacityofthesoil,orthecapacityofthesoilfoundationsystemincludingfooting,pile,pierorcaissonandthesoil,shallbesufficienttosupportthestructurewithallprescribedloads,consideringthesettlementofthestructure. For piles, this refers to pile capacity as determined by pilesoil friction and bearing whichmay bedeterminedinaccordancewiththeprovisionsofChapter3.Fortheloadcombinationincludingearthquake,thesoilcapacity shallbe sufficient to resist loads at acceptable strains consideringboth the short time loading and thedynamicpropertiesofthesoil.ThestressandsettlementofsoilunderappliedloadsshallbedeterminedbasedonestablishedmethodsofSoilMechanics.

1.8.3 SUPERSTRUCTURETOFOUNDATIONCONNECTIONTheconnectionofsuperstructureelementstothefoundationshallbeadequatetotransmittothefoundationtheforcesforwhichtheelementsarerequiredtobedesigned.

Chapter1

23

1.8.4 FOUNDATIONSOILINTERFACEFor regular buildings the baseoverturningmoments for the entire structureor for anyoneof its lateral forceresisting elements, shall not exceed twothirds of the dead load resisting moment. The weight of the earthsuperimposedoverfootingsmaybeusedtocalculatethedeadloadresistingmoment.

1.8.5 SPECIALREQUIREMENTSFORFOOTINGS,PILESANDCAISSONSINSEISMICZONES2,3AND4

1.8.5.1 PILESANDCAISSONSPilesandcaissons shallbedesigned for flexurewhenever the topof suchmembers isanticipated tobe laterallydisplacedbyearthquakemotions.ThecriteriaanddetailingrequirementsofSec8.3forconcreteandSec10.20forsteelshallapplyforalengthofsuchmembersequalto120percentoftheflexurallength.

1.8.5.2 FOOTINGINTERCONNECTIONa. Footingsandpilecapsshallbecompletely interconnectedbystruttiesorotherequivalentmeans

torestraintheirlateralmovementsinanyorthogonaldirection.

b. Thestruttiesorotherequivalentmeansasspecified in (a)above,shallbecapableofresisting intensionorcompressionaforcenotlessthan10%ofthelargerfootingorcolumnloadunlessitcanbedemonstratedthatequivalentrestraintcanbeprovidedbyfrictionalandpassivesoilresistanceorbyotherestablishedmeans.

1.8.6 RETAININGWALLDESIGNRetainingwallsshallbedesignedtoresistthelateralpressureoftheretainedmaterial,underdrainedorundrainedconditions and including surcharge, in accordance with established engineering practice. For such walls, theminimumfactorofsafetyagainstbaseoverturningandslidingduetoappliedearthpressureshallbe1.5.

1.9 DESIGNANDCONSTRUCTIONREVIEWEverybuildingorstructuredesignedshallhaveitsdesigndocumentspreparedinaccordancewiththeprovisionsofSec1.9.1.TheminimumrequirementsfordesignreviewandconstructionobservationshallbethosesetforthunderSec1.9.2and1.9.3respectively.

1.9.1 DESIGNDOCUMENTThedesigndocumentsshallbepreparedandsignedby theengineer responsible for the structuraldesignofanybuilding or structure intended for construction. The design documents shall include a design report,materialspecificationsandasetofstructuraldrawings,whichshallbepreparedincompliancewithSec1.9.2and1.9.3belowforsubmittaltotheconcernedauthority.Forthepurposeofthisprovision,theconcernedauthorityshallbeeitherpersonsfromthegovernmentapprovalagencyfortheconstruction,ortheownerofthebuildingorthestructure,oroneofhisrepresentatives.

1.9.2 DESIGNREPORTThedesignreportshallcontainthedescriptionofthestructuraldesignwithbasicdesign informationasprovidedbelow,sothatanyotherstructuraldesignengineerwillbeabletoindependentlyverifythedesignparametersandthemembersizesusingthesebasicinformation.Thedesignreportshallinclude,butnotbelimitedto,thefollowing:

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a) Name and governing edition of thisCode andother referenced standards, and the specificportions, stating chapter, section, clause etc. of these Code and standards including anyspecialistreportusedforthestructuraldesign.

b) Methodsusedforthecalculationofallapplied loadsalongwith basic loadcoefficientsandother basic information including any assumption or judgment made under specialcircumstances.

c) Adrawingof thecompletemathematicalmodelprepared inaccordancewithSec1.2.7.1 torepresent the structureand showingon it thevalues, locationsanddirectionsofallappliedloads,andlocationofthelateralloadresistingsystemssuchasshearwalls,bracedframesetc.

d) Methodsofstructuralanalysis,andresultsoftheanalysissuchasshear,moment,axialforceetc., used for proportioning various structural members and joints including foundationmembers.

e) Methods of structural design including types and strength of thematerials of constructionusedforproportioningthestructuralmembers.

f) Reference of the soil report or any other documents used in the design of the structure,foundationorcomponentsthereof.

g) Statementsupportingthevalidityoftheabovedesigndocumentswithdateandsignatureoftheengineerresponsibleforthestructuraldesign.

h) When computer programs are used, to any extent, to aid in the analysis or design of thestructure,thefollowingitems,inadditiontoitems(a)through(g)above,shallberequiredtobeincludedinthedesignreport:

i. Asketchofthemathematicalmodelusedtorepresentthestructure inthecomputergeneratedanalysis.

ii. The computer output containing the date of processing, program identification,identificationof structuresbeinganalysed,all inputdata,unitsand final results.Thecomputer input data shall be clearly distinguished from those computed in theprogram.

iii. Aprogramdescription containing the informationnecessary to verify the inputdataand interpret the results todetermine thenature and extentof the analysis and tocheckwhetherthecomputationscomplywiththeprovisionsofthisCode.

iv. Thefirstsheetofeachcomputerrunshallbesignedbytheengineerresponsibleforthestructuraldesign.

1.9.3 STRUCTURALDRAWINGSANDMATERIALSPECIFICATIONSThestructuraldrawingsshallinclude,butnotbelimitedto,thefollowing:

a) Thefirstsheetshallcontain:(1)identificationoftheprojecttowhichthebuildingorthestructure,orportionthereofbelongs,(2)referencetothedesignreportspecifiedinSec1.9.2above,(3)dateofcompletionofdesign,and(4)identificationandsignaturewithdateoftheengineerresponsibleforthestructuraldesign.

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b) The second sheet shall containdetailmaterial specifications showing : (1)Specified compressivestrengthof concreteat statedagesor stagesof construction forwhicheachpartof structure isdesigned (2)Specified strengthor gradeof reinforcement (3)Specified strengthofprestressingtendonsorwires(4)Specifiedstrengthorgradeofsteel(5)Specifiedstrengthsforbolts,weldsetc.(6) Specified strength of masonry, timber, bamboo, ferrocement (7) Minimum concretecompressivestrengthattimeofposttensioning(8)Stressingsequenceforposttensioningtendons(9)Generalnotes indicating clear cover, development lengthsof reinforcements,or anyotherdesign parameter relevant to the member or connection details provided in drawings to befollowed,asapplicable,and(10)identificationandsignaturewithdateoftheengineerresponsibleforthestructuraldesign.

c) Drawing sheets,other than the first two, shall include structural detailsof the elementsof thestructure clearly showing all sizes, crosssections and relative locations, connections,reinforcements, laps, stiffeners,welding types, lengthsand locationsetc.whichever isapplicableforaparticularconstruction. Floor levels, columncentresandoffsetetc., shallbedimensioned.Camber of trusses and beams, if required, shall be shown on drawings. For bolt connectedmembers,connectiontypessuchasslip,critical,tensionorbearingtype,shallbeindicatedonthedrawing.

d) Drawingsshallbepreparedtoascalelargeenoughtoshowtheinformationclearlyandthescalesshallbemarkedonthedrawingsheets.Ifanyvariationfromthedesignspecificationsprovided insheettwooccurs,thedrawingsheetshallbeprovidedadditionallywiththedesignspecificationsincludingmaterialtypesandstrength,clearcoveranddevelopment lengthsofreinforcements,oranyotherdesignparameterrelevanttothememberorconnectiondetailsprovidedinthatdrawingsheet.Eachdrawingsheetshallalsocontainthesignaturewithdateoftheengineerresponsibleforthestructuraldesign.

1.9.4 DESIGNREVIEWThedesigndocumentsspecifiedinSec1.9.1shallbeavailableforreviewwhenrequiredbytheconcernedauthority.Reviewshallbeaccomplishedbyan independentstructuralengineerqualified for this taskandappointedby theconcernedauthority.Designreviewshallbeperformedthroughindependentcalculations,basedontheinformationprovided in thedesign documents prepared and signedby theoriginal structural design engineer, to verify thedesignparameters includingapplied loads,methodsofanalysisanddesign,andfinaldesigndimensionsandotherdetailsof thestructuralelements.The reviewingengineershallalsocheck thesufficiencyandappropriatenessofthesuppliedstructuraldrawingsforconstruction.

1.9.5 CONSTRUCTIONOBSERVATIONConstruction observation shall be performed by a responsible person who will be a competent professionalappointedbytheownerofthebuildingorthestructure.Constructionobservationshallinclude,butnotbelimitedto,thefollowing:

a. Specificationofanappropriatetestingand inspectionschedulepreparedandsignedwithdatebytheresponsibleperson;

b. Reviewoftestingandinspectionreports;and

c. Regular site visit to verify the general compliance of the constructionworkwith the structuraldrawingsandspecificationsprovidedinSec1.9.3above.

Chapter 2

LOADSONBUILDINGSANDSTRUCTURES

2.1 INTRODUCTION

2.1.1 SCOPEThischapter specifies theminimumdesign forces includingdead load, live load,windandearthquake loads,miscellaneousloadsandtheirvariouscombinations.TheseloadsshallbeapplicableforthedesignofbuildingsandstructuresinconformancewiththegeneraldesignrequirementsprovidedinChapter1.

2.1.2 LIMITATIONSProvisionsofthischaptershallgenerallybeappliedtomajorityofbuildingsandotherstructurescoveredinthiscode subject to normally expected loading conditions. For those buildings and structures having unusualgeometricalshapes,responsecharacteristicsorsite locations,orforthosesubjecttospecial loading includingtornadoes, specialdynamicorhydrodynamic loadsetc., sitespecificorcasespecificdataoranalysismayberequired todetermine thedesign loadson them. In suchcases,andallothercases forwhich loadsarenotspecifiedinthischapter,loadinginformationmaybeobtainedfromreliablereferencesorspecialistadvicemaybesought.However,suchloadsshallbeappliedincompliancewiththeprovisionsofotherpartsorsectionsofthisCode.

2.2 DEADLOADS

2.2.1 GENERALTheminimumdesigndeadloadforbuildingsandportionsthereofshallbedeterminedinaccordancewiththeprovisionsofthissection.Inaddition,designoftheoverallstructureanditsprimaryloadresistingsystemsshallconformtothegeneraldesignprovisionsgiveninChapter1.

2.2.2 DEFINITIONDeadLoad isthevertical loadduetotheweightofpermanentstructuralandnonstructuralcomponentsandattachmentsofabuildingsuchaswalls,floors,ceilings,permanentpartitionsandfixedserviceequipmentetc.

2.2.3 ASSESSMENTOFDEADLOADDeadloadforastructuralmembershallbeassessedbasedontheforcesdueto:

weightofthememberitself, weightofallmaterialsofconstructionincorporatedintothebuildingtobesupportedpermanentlyby

themember,

weightofpermanentpartitions, weightoffixedserviceequipment,and neteffectofprestressing.

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2.2.4 WEIGHTOFMATERIALSANDCONSTRUCTIONSInestimatingdeadloads,theactualweightsofmaterialsandconstructionsshallbeused,providedthatintheabsenceofdefiniteinformation,theweightsgiveninTables2.2.1and2.2.2shallbeassumedforthepurposesofdesign.

Table2.2.1:UnitWeightofBasicMaterials

Material

Unitweight(kN/m3) Material

UnitWeight(kN/m3)

AluminiumAsphaltBrassBronzeBrickCementCoal,looseConcretestoneaggregate(unreinforced)brickaggregate(unreinforced)CopperCork,normalCork,compressedGlass,window(sodalime)

27.021.283.687.718.914.78.822.8*20.4*86.41.73.725.5

Granite,BasaltIroncastwroughtLeadLimestoneMarbleSand,drySandstoneSlateSteelStainlessSteelTimberZinc

26.470.775.4111.024.526.415.722.628.377.078.755.911.070.0

*forreinforcedconcrete,add0.63kN/m3foreach1%byvolumeofmainreinforcement

2.2.5 WEIGHTOFPERMANENTPARTITIONSWhen partitionwalls are indicated on the plans, theirweight shall be considered as dead load acting asconcentratedlineloadsintheiractualpositionsonthefloor.Theloadsduetoanticipatedpartitionwalls,whicharenotindicatedontheplans,shallbetreatedasliveloadsanddeterminedinaccordancewithSec2.3.2.4.

2.2.6 WEIGHTOFFIXEDSERVICEEQUIPMENTWeights of fixed service equipment and other permanentmachinery, such as electrical feeders and othermachinery,heating,ventilatingandairconditioningsystems,liftsandescalators,plumbingstacksandrisersetc.shallbeincludedasdeadloadwheneversuchequipmentaresupportedbystructuralmembers.

2.2.7 ADDITIONALLOADSInevaluating the finaldead loadsonastructuralmember fordesignpurposes,allowancesshallbemade foradditional loads resulting from the (i) difference between the prescribed and the actual weights of themembersandconstructionmaterials;(ii) inclusionoffuture installations;(iii)changes in occupancyoruseofbuildings;and(iv)inclusionofstructuralandnonstructuralmembersnotcoveredinSec2.2.2and2.2.3.

2.3 LIVELOADS

2.3.1 GENERALTheliveloadsusedforthestructuraldesignoffloors,roofandthesupportingmembersshallbethegreatestappliedloadsarisingfromtheintendeduseoroccupancyofthebuilding,orfromthestackingofmaterialsandtheuseofequipmentandproppingduringconstruction,but shallnotbe less than theminimumdesign liveloadssetoutby theprovisionsof thissection.For thedesignofstructuralmembers for forces including liveloads,requirementsoftherelevantsectionsofChapter1shallalsobefulfilled.

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Table2.2.2DeadLoad

Material/Component/Member

WeightperUnitArea(kN/m2)

MaterialWeightperUnitArea(kN/m2)

FloorAsphalt,25mmthickClaytiling,13mmthickConcreteslab(stoneaggregate)* solid,100mmthick solid,150mmthickGalvanizedsteelfloordeck(excl.topping)Magnesiumoxychloride normal(sawdustfiller),25mmthick heavyduty(mineralfiller),25mmthickTerrazzopaving16mmthickRoofAcrylicresinsheet,corrugated 3mmthick,standardcorrugations 3mmthick,deepcorrugationsAsbestoscement,corrugatedsheeting (incl.lapandfastenings) 6mmthick(standardcorrugations) 6mmthick(deepcorrugations)Aluminium,corrugatedsheeting (incl.lapandfastenings) 1.2mmthick 0.8mmthick 0.6mmthickAluminiumsheet(plain) 1.2mmthick 1.0mmthick 0.8mmthickBituminousfelt(5ply)andgravelSlates 4.7mmthick 9.5mmthickSteelsheet,flatgalvanized 1.00mmthick 0.80mmthick 0.60mmthickSteel,galvanizedstd.corrugatedsheeting (incl.lapandfastenings) 1.0mmthick 0.8mmthick 0.6mmthickTiles terracotta(Frenchpattern) concrete,25mmthick claytiles

0.5260.2682.3603.5400.1470.3830.3450.5270.4310.0430.0620.1340.1580.0480.0280.0240.0330.0240.0190.4310.3350.6710.0820.0670.0530.1200.0960.0770.5750.5270.60.9

WallsandPartitionsAcrylic resin sheet, flat, per mmthicknessAsbestoscementsheeting 4.5mmthick 6.0mmthickBrickmasonrywork,excl.plaster burnt clay, per 100 mmthickness sandlime, per 100 mmthicknessConcrete(stoneaggregate)* 100mmthick 150mmthick 250mmthickFibre insulation board, per 10 mmthicknessFibrous plaster board, per 10 mmthicknessGlass,per10mmthicknessHardboard,per10mmthicknessParticle or flake board, per 10 mmthicknessPlasterboard,per10mmthicknessPlywood,per10mmthicknessCeilingFibrousplaster,10mmthickCementplaster,13mmthickSuspendedmetallathandplaster (twofacedincl.studding)MiscellaneousFelt(insulating),per10mmthicknessPlaster cement,per10mmthickness lime,per10mmthicknessPVCsheet,per10mmthicknessRubberpaving,per10mmthicknessTerracottaHollowBlockMasonry 75mmthick 100mmthick 150mmthick

0.0120.0720.1061.9101.9802.3603.5405.9000.0340.0920.2690.9610.0750.0920.0610.0810.2870.4800.0190.2300.1910.1530.1510.6710.9951.388

*forbrickaggregate,90%ofthelistedvaluesmaybeused.

2.3.2 DEFINITIONLive load is the loadsuperimposedby theuseoroccupancyof thebuildingnot including theenvironmentalloadssuchaswindload,rainload,earthquakeloadordeadload.

2.3.3 MINIMUMFLOORLIVELOADSTheminimum floor live loads shallbe thegreatestactual imposed loads resulting from the intendeduseoroccupancyofthefloor,andshallnotbelessthantheuniformlydistributedloadpatternsspecifiedinSec2.3.4ortheconcentratedloadsspecifiedinSec2.3.5whicheverproducesthemostcriticaleffect.Theliveloadsshallbeassumedtoactverticallyupontheareaprojectedonahorizontalplane.

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Table2.3.1MinimumUniformlyDistributedLiveLoads,AndMinimumConcentratedLiveLoadsOccupancyorUse Uniform

kN/m2Conc.kN

Apartments(seeResidential) Accessfloorsystems Officeuse Computeruse

2.44.79

8.98.9

Armoriesanddrillrooms 7.18 Assemblyareasandtheaters Fixedseats(fastenedtofloor) Lobbies

Movableseats Platforms(assembly) Stagefloors

2.874.794.794.797.18

Balconies(exterior)Ononeandtwofamilyresidencesonly,andnotexceeding19.3m2

4.792.87

Bowlingalleys,poolrooms,andsimilarrecreationalareas 3.59 Catwalksformaintenanceaccess 1.92 1.33CorridorsFirstfloor Otherfloors,sameasoccupancyservedexceptasindicated

4.79

Dancehallsandballrooms 4.79Decks(patioandroof)Sameasareaserved,orforthetypeofoccupancyaccommodated

Diningroomsandrestaurants 4.79 Dwellings(seeResidential)

Elevatormachineroomgrating(onareaof2,580mm2) 1.33

Finishlightfloorplateconstruction (onareaof645mm2) 0.89

Fireescapes Onsinglefamilydwellingsonly

4.791.92

Fixedladders SeeSection2.3.11Garages(passengervehiclesonly)Trucksandbuses 1.92a,bGrandstands(seeStadiumsandarenas,Bleachers) Gymnasiumsmainfloorsandbalconies 4.79Handrails,guardrails,andgrabbars SeeSection2.3.11HospitalsOperatingrooms,laboratoriesPatientroomsCorridorsabovefirstfloor

2.871.923.83

4.454.454.45

Hotels(seeResidential) LibrariesReadingroomsStackroomsCorridorsabovefirstfloor

2.87

7.18c3.83

4.454.454.45

ManufacturingLightHeavy

6.0011.97

8.9013.40

Marquees 3.59OfficeBuildingsFileandcomputerroomsshallbedesignedforheavierloads basedonanticipatedoccupancy LobbiesandfirstfloorcorridorsOfficesCorridorsabovefirstfloor

4.792.403.83

8.908.908.90

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Table2.3.1MinimumUniformlyDistributedLiveLoads,AndMinimumConcentratedLiveLoads(Contd.)

PenalInstitutions Cellblocks Corridors

1.924.79

ResidentialDwellings(oneandtwofamily)

UninhabitableatticswithoutstorageUninhabitableatticswithstorageHabitableatticsandsleepingareasAllotherareasexceptstairsandbalconies

HotelsandmultifamilyhousesPrivateroomsandcorridorsservingthemPublicroomsandcorridorsservingthem

0.480.961.441.92

1.924.79

Reviewingstands,grandstands,andbleachers 4.79d

RoofsOrdinaryflat,pitched,andcurvedroofsRoofsusedforpromenadepurposesRoofsusedforroofgardensorassemblypurposesRoofsusedforotherspecialpurposesAwningsandcanopiesFabricconstructionsupportedbyalightweightrigidskeletonstructureAllotherconstruction

Primaryroofmembers,exposedtoaworkfloorSinglepanelpointoflowerchordofrooftrussesoranypointalongprimary

structuralmemberssupportingroofsovermanufacturing,storagewarehouses,andrepairgarages

AllotheroccupanciesAllroofsurfacessubjecttomaintenanceworkers

0.96h2.874.79i

0.24(nonreduceable)0.96

i

8.9

1.331.33

SchoolsClassroomsCorridorsabovefirstfloorFirstfloorcorridors

1.923.834.79

4.454.454.45

Scuttles,skylightribs,andaccessibleceilings 0.89Sidewalks,vehiculardriveways,andyardssubjecttotrucking 11.97e 35.60fStadiumsandarenas

BleachersFixedseats(fastenedtofloor)

4.79d2.87d

StairsandexitwaysOneandtwofamilyresidencesonly

4.791.92

g

Storageareasaboveceilings 0.96 Storagewarehouses(shallbedesignedforheavierloadsifrequiredfor

anticipatedstorage) Light

Heavy

6.0011.97

StoresRetail

FirstfloorUpper loorsWholesale,allfloors

4.793.596.00

4.454.454.45

Vehiclebarriers SeeSection2.3.11Walkwaysandelevatedplatforms(otherthanexitways) 2.87 Yardsandterraces,pedestrian 4.79

aFloorsingaragesorportionsofabuildingusedforthestorageofmotorvehiclesshallbedesignedfortheuniformlydistributedliveloadsofTable2.3.1orthefollowingconcentratedload:(1)forgaragesrestrictedtopassengervehiclesaccommodatingnotmorethanninepassengers,13.35kNactingonanareaof114mmby114mmfootprintofajack;and(2)formechanicalparkingstructureswithoutslabordeckthatareusedforstoringpassengercaronly,10kNperwheel.

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bGaragesaccommodatingtrucksandbusesshallbedesignedinaccordancewithanapprovedmethod,whichcontainsprovisionsfortruckandbusloadings.

cTheloadingappliestostackroomfloorsthatsupportnonmobile,doublefacedlibrarybookstackssubjecttothefollowinglimitations:(1)Thenominalbook stackunitheightshallnotexceed2290mm;(2)thenominalshelfdepthshallnotexceed305mmforeachface;and(3)parallelrowsof doublefacedbookstacksshallbeseparatedbyaislesnotlessthan914mmwide.dInadditiontotheverticalliveloads,thedesignshallincludehorizontalswayingforcesappliedtoeachrowoftheseatsasfollows:0.350kNperlinearmeterofseatappliedinadirectionparalleltoeachrowofseatsand0.15kNperlinearmeterofseatappliedinadirectionperpendiculartoeachrowofseats.Theparallelandperpendicularhorizontalswayingforcesneednotbeappliedsimultaneously.

eOtheruniformloadsinaccordancewithanapprovedmethod,whichcontainsprovisionsfortruckloadings,shallalsobeconsideredwhereappropriate.fTheconcentratedwheelloadshallbeappliedonanareaof114mmby114mmfootprintofajack.gMinimumconcentratedloadonstairtreads(onareaof2,580mm2)is1.33kN.hWhereuniformroofliveloadsarereducedto lessthan1.0kN/m2 inaccordancewithSection2.3.14.1andareappliedtothedesignofstructural membersarrangedsoastocreatecontinuity,thereducedroofliveloadshallbeappliedtoadjacentspansortoalternatespans,whicheverproducesthegreatest unfavorableeffect.iRoofsusedforotherspecialpurposesshallbedesignedforappropriateloadsasapprovedbytheauthorityhavingjurisdiction.

2.3.4 UNIFORMLYDISTRIBUTEDLOADSTheuniformlydistributed live loadshallnotbe less than thevalues listed inTable2.3.1, reducedasmaybespecified inSec2.3.13,applieduniformlyovertheentireareaofthefloor,oranyportionthereoftoproducethemostadverseeffectsinthememberconcerned.

2.3.5 CONCENTRATEDLOADSTheconcentrated loadtobeappliednonconcurrentlywith theuniformlydistributed loadgiven inSec2.3.4,shallnotbe less than that listed inTable2.3.1.Unlessotherwise specified inTable2.3.1or in the followingparagraph,theconcentratedloadshallbeappliedoveranareaof300mmx300mmandshallbelocatedsoastoproducethemaximumstressconditionsinthestructuralmembers.

Inareaswherevehiclesareusedorstored,suchascarparkinggarages,ramps,repairshopsetc.,provisionshallbemadeforconcentratedloadsconsistingoftwoormoreloadsspacednominally1.5moncentresinabsenceoftheuniformliveloads.Eachloadshallbe40percentofthegrossweightofthemaximumsizevehicletobeaccommodatedandappliedoveranareaof750mmx750mm.For the storageofprivateorpleasuretypevehicleswithout repairor fuelling, floors shallbe investigated in theabsenceof theuniform live load, foraminimumconcentratedwheel loadof 9kN spaced1.5moncentres,appliedoveranareaof750mmx750mm. The uniform live loads for these cases are provided in Table 2.3.1 The condition of concentrated oruniformliveloadproducingthegreaterstressesshallgovern.

2.3.6 PROVISIONFORPARTITIONWALLSWhenpartitions,not indicatedontheplans,areanticipatedtobeplacedonthe floors,theirweightshallbeincludedasanadditional live load actingas concentrated line loads inan arrangementproducing themostsevereeffectonthefloor,unless itcanbeshownthatamorefavourablearrangementofthepartitionsshallprevailduringthefutureuseofthefloor.

Inthecaseoflightpartitions,whereinthetotalweightpermetrerunisnotgreaterthan5.5kN,auniformlydistributed live loadmaybeappliedonthefloor in lieuoftheconcentrated line loadsspecifiedabove.Suchuniformliveloadpersquaremetreshallbeatleast33%oftheweightpermetrerunofthepartitions,subject

toaminimumof1.2kN/m2.

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2.3.7 MORETHANONEOCCUPANCYWhereanareaofafloorisintendedfortwoormoreoccupanciesatdifferenttimes,thevaluetobeusedfromTable2.3.1shallbethegreatestvalueforanyoftheoccupanciesconcerned.

2.3.8 MINIMUMROOFLIVELOADSRoofliveloadsshallbeassumedtoactverticallyovertheareaprojectedbytherooforanyportionofituponahorizontalplane,andshallbedeterminedasspecifiedinthefollowingsections:

2.3.8.1 REGULARPURPOSEFLAT,PITCHEDANDCURVEDROOFSLiveloadsonregularpurposeroofsshallbethegreatestappliedloadsproducedduringusebymovableobjectssuchasplantersandpeople,andthoseinducedduringmaintenancebyworkers,equipmentandmaterialsbutshallnotbelessthanthosegiveninTable2.3.2.

2.3.8.2 SPECIALPURPOSEROOFSForspecialpurposeroofs, live loadsshallbeestimatedbasedontheactualweightdependingonthetypeofuse,butshallnotbelessthanthefollowingvalues:

a)roofsusedforpromenadepurposes 3.0kN/m2

b)roofsusedforassemblypurposes 5.0kN/m2

c)roofsusedforgardens 5.0kN/m2

d)roofsusedforotherspecialpurposestobedeterminedasperSec2.3.9

2.3.8.3 ACCESSIBLEROOFSUPPORTINGMEMBERSRooftrussesoranyotherprimaryroofsupportingmemberbeneathwhichafullceilingisnotprovided,shallbecapableofsupportingsafely, inadditiontootherroof loads,aconcentrated loadatthe locationsasspecifiedbelow:

a) Industrial, Storage and Garage Buildings Any single panel point of thelowerchordofaroof truss,oranypointofotherprimaryroofsupportingmember

9.0kN

b) BuildingwithOtherOccupanciesAnysinglepanelpointofthelowerchordofarooftruss,oranypointofotherprimaryroofsupportingmember

1.3kN

2.3.9 LOADSNOTSPECIFIEDLive loads,notspecifiedforusesoroccupancies inSec2.3.3,2.3.4and2.3.5,shallbedeterminedfrom loadsresultingfrom:a) weightoftheprobableassemblyofpersons;b) weightoftheprobableaccumulationofequipmentandfurniture,andc) weightoftheprobablestorageofmaterials.

2.3.10 PARTIALLOADINGANDOTHERLOADINGARRANGEMENTSThe full intensityof theappropriately reduced live loadappliedonly toaportionof the lengthorareaofastructureormember shallbeconsidered, if itproducesamoreunfavourableeffect than the same intensityappliedoverthefulllengthorareaofthestructureormember.Where uniformly distributed live loads are used in the design of continuousmembers and their supports,considerationshallbegiventofulldeadloadonallspansincombinationwithfullliveloadsonadjacentspansandonalternatespanswhicheverproducesamoreunfavourableeffect.

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Table2.3.2:MinimumRoofLiveLoads(1)TypeandSlopeofRoof Distributed

Load,kN/m2ConcentratedLoad,kN

I Flatroof(slope=0) 1.5 1.8

II 1.Pitchedorslopedroof(0

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Table2.3.3:MiscellaneousLiveLoadsStructuralMemberorComponent LiveLoad(1)

(kN/m)1. Handrails,parapetsandsupports: a)Lightaccessstairs,gangwaysetc. i) width0.6m ii) width>0.6m b)Staircasesotherthanin(a)above,ramps,balconies: i) Singledwellingandprivate ii) Staircasesinresidentialbuildings iii) Balconiesorportionthereof,standsetc.having fixedseatswithin0.55mofthebarrier vi) Publicassemblybuildingsincludingtheatres, cinemas,assemblyhalls,stadiums,mosques, churches,schoolsetc.vi) Buildingsandoccupanciesotherthan(i)through(iv)above

0.250.350.350.351.53.00.75

2. Vehiclebarriersforcarparksandramps: a) Forvehicleshavinggrossmass2500kg b) Forvehicleshavinggrossmass>2500kg c) Forrampsofcarparksetc.

100(2)165(2)seenote(3)

Note: (1) Theseloadsshallbeappliednonconcurrentlyalonghorizontalandverticaldirections, exceptasspecifiedinnote(2)below.

(2) Theseloadsshallbeappliedonlyinthehorizontaldirection,uniformlydistributedover anylengthof1.5mofabarrierandshallbeconsideredtoactatbumperheight.Forcase 2(a)bumperheightmaybetakenas375mmabovefloorlevel.

(3) Barrierstoaccessrampsofcarparksshallbedesignedforhorizontalforcesequalto 50%ofthosegivenin2(a)and2(b)appliedatalevelof610mmabovetheramp. Barrierstostraightexitrampsexceeding20minlengthshallbedesignedfor horizontalforcesequaltotwicethevaluesgivenin2(a)and2(b).

Table2.3.4:MinimumLiveLoadsonSupportsandConnectionsofEquipmentduetoImpact(1)EquipmentorMachinery Additionalloadduetoimpactaspercentage

ofstaticloadincludingselfweight Vertical Horizontal1. Lifts,hoistsandrelatedoperating

machinery100%

2. Lightmachinery(shaftormotordriven) 20% 3. Reciprocatingmachinery,orpowerdriven

units.50%

4. Hangerssupportingfloorsandbalconies 33% 5. Cranes:

a)Electricoverheadcranes 25%ofmaximumwheelload

i)Transversetotherail:20%oftheweightoftrolleyandliftedloadonly,appliedonehalfatthetopofeachrail

ii)Alongtherail:

10%ofmaximumwheelloadappliedatthetopofeachrail

b)Manuallyoperatedcranes 50%ofthevaluesin(a)above

50%ofthevaluesin(a)above

c)Caboperatedtravellingcranes 25%

NotapplicableNote:(1)

Alltheseloadsshallbeincreasedifsorecommendedbythemanufacturer.Formachineryandequipmentnotlisted,impactloadsshallbethoserecommendedbythemanufacturers,ordeterminedbydynamicanalysis.

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2.3.13.2 HEAVYLIVELOADS.Liveloadsthatexceed4.79kN/m2shallnotbereduced.EXCEPTION:Liveloadsformemberssupportingtwoormorefloorsmaybereducedby20percent.

2.3.13.3 PASSENGERCARGARAGES.Theliveloadsshallnotbereducedinpassengercargarages.EXCEPTION:Liveloadsformemberssupportingtwoormorefloorsmaybereducedby20percent.

2.3.13.4 SPECIALOCCUPANCIES.

Liveloadsof4.79kN/m2orlessshallnotbereducedinpublicassemblyoccupancies. Thereshallbenoreductionofliveloadsforcycloneshelters.

2.3.13.5 LIMITATIONSONONEWAYSLABS.Thetributaryarea,AT,foronewayslabsshallnotexceedanareadefinedbytheslabspantimesawidthnormaltothespanof1.5timestheslabspan.

2.3.14 REDUCTIONINROOFLIVELOADSTheminimumuniformlydistributedroofliveloads,LoinTable2.3.1,arepermittedtobereducedaccordingtothefollowingprovisions.

2.3.14.1 FLAT,PITCHED,ANDCURVEDROOFS.Ordinaryflat,pitched,andcurvedroofsarepermittedtobedesignedforareducedroofliveload,asspecifiedinEq.2.3.2orothercontrollingcombinationsof loads,asdiscussed later in thischapter,whicheverproducesthegreater load. In structures suchasgreenhouses,where special scaffolding isusedasawork surface forworkmenandmaterialsduringmaintenanceandrepairoperations,alowerroofloadthanspecifiedinEq.2.3.2shallnotbeusedunlessapprovedbytheauthorityhaving jurisdiction.Onsuchstructures,theminimumroofliveloadshallbe0.58kN/m2.

Lr=LoR1R2where0.58Lr0.96 (2.3.2)

where

Lr=reducedroofliveloadperm2ofhorizontalprojectioninkN/m2

ThereductionfactorsR1andR2shallbedeterminedasfollows:

R1=1forAt18.58m2

=1.20.011Atfor18.58m2

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where,forapitchedroof,F=0.12slope,withslopeexpressedinpercentagepointsand,foranarchordome,F=risetospanratiomultipliedby32.

2.3.14.2 SPECIALPURPOSEROOFS.Roofsthathaveanoccupancyfunction,suchasroofgardens,assemblypurposes,orotherspecialpurposesarepermittedtohavetheiruniformlydistributedliveloadreducedinaccordancewiththerequirementsofSection2.3.13.

Table2.3.5LiveLoadElementFactor,KLL

Element KLL

InteriorcolumnsExteriorcolumnswithoutcantileverslabs

44

Edgecolumnswithcantileverslabs 3

CornercolumnswithcantileverslabsEdgebeamswithoutcantileverslabsInteriorbeams

222

Allothermembersnotidentifiedincluding:EdgebeamswithcantileverslabsCantileverbeamsOnewayslabsTwowayslabsMemberswithoutprovisionsforcontinuoussheartransfernormaltotheirspan

1

aInlieuoftheprecedingvalues,KLL ispermittedtobecalculated.

2.4 WINDLOADS

2.4.1 GENERALScope: Buildings and other structures, including theMain WindForce Resisting System (MWFRS) and allcomponentsandcladdingthereof,shallbedesignedandconstructedtoresistwindloadsasspecifiedherein.

Allowed Procedures: The designwind loads for buildings and other structures, including theMWFRS andcomponentandcladdingelementsthereof,shallbedeterminedusingoneofthefollowingprocedures:

(1)Method1Simplified Procedure as specified in Section 2.4.4 for buildings and structuresmeeting therequirementsspecifiedtherein;

(2)Method 2Analytical Procedure as specified in Section 2.4.5 for buildings and structuresmeeting therequirementsspecifiedtherein;

(3)Method3WindTunnelProcedureasspecifiedinSection2.4.18.

WindPressures:Actingonoppositefacesofeachbuildingsurface.Inthecalculationofdesignwind loadsfortheMWFRS and for components and cladding for buildings, the algebraic sum of the pressures acting onoppositefacesofeachbuildingsurfaceshallbetakenintoaccount.

2.4.1.1 MINIMUMDESIGNWINDLOADINGThedesignwindload,determinedbyanyoneoftheproceduresspecifiedinSection2.4.1,shallbenotlessthanspecifiedinthissection.

MainWindForceResistingSystem:ThewindloadtobeusedinthedesignoftheMWFRSforanenclosedorpartiallyenclosedbuildingorother structure shallnotbe less than0.5kN/m2multipliedby theareaof the

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buildingorstructureprojectedontoaverticalplanenormalto theassumedwinddirection.Thedesignwindforceforopenbuildingsandotherstructuresshallbenotlessthan0.5kN/m2)multipliedbytheareaAf.

ComponentsandCladding:Thedesignwindpressureforcomponentsandcladdingofbuildingsshallnotbelessthananetpressureof0.5kN/m2actingineitherdirectionnormaltothesurface.

2.4.2 DEFINITIONSThefollowingdefinitionsapplyonlytotheprovisionsofSection2.4: