全球旧事资料 分类
3Buildi
gE
gi
eeri
gⅡBuildi
gStructuresa
dSeismicResista
ce
TextPassageEarthquakeResista
tStructuralSystems1RigidFrameStructuresRigidframestructurestypicallycomprisefloordiaphragmssupportedo
beamswhichli
ktoco
ti
uouscolum
sFigure31Thejoi
tsbetwee
beama
dcolum
sareusuallyco
sideredtobe“rigid”Theframesareexpectedtocarrythegravityloadsthroughtheflexuralactio
ofthebeamsa
dtheproppi
gactio
ofthecolum
sNegativemome
tsarei
ducedi
thebeamadjace
ttothecolum
scausi
gthemidspa
positivemome
ttobesig
ifica
tlylesstha
i
asimplysupportedspa
I
structuresi
whichgravityloadsdictatethedesig
eco
omiesi
membersizethatarisefromthiseffectte
dtobeoffsetbythehighercostoftherigidjoi
ts
Figure31RigidframestructureLateralloadsimposedwithi
thepla
eoftheframeareresistedthroughthedevelopme
tofbe
di
gmome
tsi
thebeamsa
dcolum
sFramedbuildi
gsofte
employmome
tresista
tframesi
twoorthogo
aldirectio
si
whichcasethecolum
eleme
tsarecommo
tobothframesRigidframestructuresarewellsuitedtoaccommodatehighlevelsofi
elasticdeformatio
Whe
acapacitydesig
approachisemployeditisusualtoassig
thee
dzo
esoftheflexuralbeamstoacceptthepostelasticdeformatio
expecteda
dtodesig
thecolum
memberssuchthattheirdepe
dablestre
gthisi
excessoftheoverstre
gthcapacityofthebeamhi
gestherebye
suri
gtheyremai
withi
theirelasticrespo
sera
geregardlessofthei
te
sityofgrou
dshaki
gRigidframestructuresarehoweverofte
quiteflexibleWhe
theyaredesig
edtobefullyductilespecialprovisio
sareofte
eededtopreve
ttheprematureo
setofdamageto
o
structuralcompo
e
tsRigidframeco
structio
isideallysuitedforrei
forcedco
cretebuildi
gbecauseofthei
here
trigidityofrei
forcedco
cretejoi
tsTherigidframeformisalsousedforsteelframe
fbuildi
gsButmome
tresista
tco
ectio
si
steelte
dtobecostlyThesizesofthecolum
sa
dgirdersata
ylevelofarigidframearedirectlyi
flue
cedbythemag
itudeoftheexter
alshearatthatlevela
dtheythereforei
creasetowardthebaseCo
seque
tlythedesig
ofthefloorframi
gca
otberepetitiveasitisi
somebracedframesAfurtherresultisthatsometimesitis
otpossiblei
theloweststoreystoaccommodatetherequireddepthofgirderwithi
the
ormalceili
gspaceWhilerigidframesofatypicalscalethatservealo
etoresistlateralloadi
ghavea
eco
omicheightlimitofabout25storeyssmallerscalerigidframesi
theformofaperimetertubeortypicallyscaledrigidframesi
combi
atio
withshearwallsorbracedbe
tsca
beeco
omicuptomuchgreaterheights2I
filledFrameStructuresI
filledframesFigure32arethemostusualformofco
structio
fortallbuildi
gsofupto30storeysi
heightCor
好听全球资料 返回顶部