Caribbean Disaster Mitigation ProjectImplementedbytheOrganizationofAmericanStatesUnitofSustainableDevelopmentandEnvironment

fortheUSAIDOfficeofForeignDisasterAssistanceandtheCaribbeanRegionalProgram

DrawingstoAccompanytheBuildingGuidelines

SectionA:GeneralConstructionPrinciples(Figures110)Introduction|SectionA(110)|SectionA(1116)|SectionB|SectionC|SectionD|SectionE|SectionF|

SectionGDownloadAutoCADDWGfiles(ziparchive):SectionA|SectionB|SectionC|SectionsDG

FigureA1:PlanShapesofBuildings

Thesuccesswithwhichabuildingsurvivesanearthquakeissignificantlyaffectedbyitsshapeinplan.Mostbuildingswithasimplerectangularshape,withnoprojections,performwellunderearthquakeconditions,

providedtheconstructionisadequate.Longnarrowbuildingsshouldbeavoided.Longbuildingsshouldbedividedintoseparateblockswithadequateseparation.

FigureA2:SizeandLocationofWallOpenings

Thelocationandsizeofopeningsinwallshaveasignificanteffectuponthestrengthofawallanditsabilitytoresistearthquakeforces.Openingsaretobelocatedawayfromacornerbyacleardistanceofatleastoftheheightoftheopening.Itisrecommendedthataminimumdistancebe15".Thetotallengthoftheopeningsshouldnotexceedthelengthofthewallbetweenconsecutivecrosswalls.Thehorizontaldistancebetweentwoopeningsshouldnotbelessthantheheightoftheshorteropenings.

FigureA3:TypicalWallCornerDetail

FigureA4:TypicalWallJunctionDetail

FigureA5:ReinforcedMasonryGableArrangement

Animportantfactorcontributingtotheearthquakeresistanceofconcretemasonrybuildingsisthedetailingandplacingofsteelreinforcement.Thereinforcingguidesgiveninthesefiguresareonlytobeusedforsimplesinglestoreybuildingsconstructedofgoodqualityconcreteblocks.Inadditiontotheminimumverticalwallreinforcement,allwalls,cornersandjunctionsaretobereinforced.Allverticalreinforcementistobesecurelyfixedtotheringbeam.Horizontalreinforcementmustbeplacedevery3courses.Windowanddoorjambsshouldbereinforcedandtiedintothelintels.Gablewallsaretobereinforcedbybarsfixedtotheconcretebeamateavesheightandtotheslopingringbeamatthetopofthegable.

FigureA6:RecommendedMethodforConstructiononSlopingSites

Buildingssitedinexposedareas(e.g.onthebrowofahill)aremostvulnerable,whilethoseshelteredbynaturaltopographyarelessvulnerable.Insitingthebuilding,therefore,steepslopesandedgesofcliffsshouldbeavoided,aswellasotherconditionssuchassteepsidedvalleyswhereexceptionallyhighwindspeedsarefound.

Wherebuildingonasteepsiteisunavoidable,reinforcedconcretetiebeamsshouldbeconstructedtoreducetheuntiedheightofthecolumnstoamaximumof10feet,asshown.Onmoregentlyslopingsites,asatisfactorysuspendedslabmaybeachievedthroughtheuseoflooselycompactedgranularfillaspermanentformwork.

FigureA7:HipRoofConstruction

FigureA8:GableRoofConstruction

FigureA9:Rafter/RingBeamConnection

FigureA10:WallPlateConnectionandHurricaneStraps'Details

Experienceandresearchhaveshownthatflatroofsarevulnerabletohighwinds.Inanefforttoreducetheupliftingwindforcesontheroof,theroofpitchshouldbenotlessthan25to30degrees.Hiproofsshouldbeused,sincethisshapeofroofhasbeenfoundtobemorehurricaneresistantthanthegableofroof.Wheregableroofsareusedtheyshouldbestronglyconstructed.Roofoverhangsalsoexperiencehighlocalpressuresand,wherepossible,theseshouldbekepttoaminimumorremovedcompletely.Wherebuildingshaveroofedpatiosorverandas,theirroofsshouldbeseparatestructuresratherthanextensionsofthemainbuildingroof,sothatthepatioorverandahroofmaybelostwithoutendangeringthesafetyofthemainroof.Themainroofmustbesecurelyfixedtotheringbeamandridgebeams.Thismaybeachievedbytheuseofhurricanestraps.

Introduction|SectionA(110)|SectionA(1116)|SectionB|SectionC|SectionD|SectionE|SectionF|SectionG

CDMPhomepage:http://www.oas.org/en/cdmp/ ProjectContacts PageLastUpdated:20April2001