Rehabilitation and maintenance of buildings - 03Karel Mike
12ContentsProperties of materialFailures of steel
structuresTypes of refurbishmentMethods of reliability
verificationBasis of members design of steel structuresBasis of
joint designAssessment of steel structuresStrengthening of
membersStrengthening and refurbishment of structuresRefurbishment
of masonry structures using steelworkSeismic upgrading using steel
structure
SAHC - SA5 Steel structures2010T.Vran, CTU in
Prague23ConnectionsBoltedWeldedRiveted (history)
Realised:In shopOn site
Calculation:on resistanceon calculated internal forces
SAHC - SA5 Steel structures2010T.Vran, CTU in
Prague34ConnectionsBolted connectionsTypes:According to static
behaviour:Normal (no preloading)Slipresistant (controlled
tightening)
According to loading:ShearTension
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague45Bolted
connections Shear loadingCommon bolts:shearbearingSlipresistant
bolts:slipbearing
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague56Bolted
connections Shear resistancefor bolt grades 4.8, 5.8, 10.9
for other bolt grades
AsCore area of cross section of boltfubUltimate strength of
bolti Number of shear planesgM2 =1,25
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague67Bolted
connections Bearing resistance
Effect of bolt pitches
t Minimum thickness in one directiond Diameter of boltd0
Diameter of holefub Strength of boltfu Strength of material
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague78Bolted
connections Resistance of slip-resistant boltsSlip resistance
prestressing force
AsCore area of cross section of boltfubUltimate strength of
boltnNumber of friction planesmfriction coefficient ... 0,2 to
0,5
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague89
Bolted connections Bolts loaded in tensionResistance in
tension
The same resistance for common and preloaded bolts
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague910Welded
connectionsFillet welds
Butt weldsfully supply basic material
Welds = rigid connections (no slip)
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague1011
Welded connections Fillet weldsaeffective throat thickness of
the fillet welddirect stresses perpendicular to the throatshear
stresses perpendicular to the axis of weldshear stresses parallel
to the axis of welddirect stresses parallel to the axis of weld
(neglected)
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague1112Welded
connections Check of fillet weld
bwcorrelation factordepends of steel grade
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague1213
Welded connections Two fillet welds in parallel shear
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague1314Welded
connections Connection of cantileverV transferred by web:
M transferred by whole weld cross-section:
Point 1: tII, t, s Point 2: t, s
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague1415Welded
connections Flange-to-web weldLongitudinal shear flow V:
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague1516
Riveting AssemblyHeated to white heatPneumatic hammer (clamping
rivets length max. s=4,5 d)
Function (after cooling) Fully filled holeBefore riveting
diameter is by 1 mm less then hole diameterPrestressing connected
sheets
MaterialRivet from steel with lower strength than basic material
(when they are exchanged can be cut off) Head Half
spherical(Countersink)SAHC - SA5 Steel structures2010T.Vran, CTU in
Prague1617RivetingSupply at the refurbishment:Additional rivets or
bigger diameterBolts slip resistant connection, retro heads of
boltsBolts injected by epoxy
Riveting is historyExhibition on 3rd floor of Eiffel's tower
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague1718Riveted
connections - ResistanceShearShear Bearing... as for bolts
Tension
SAHC - SA5 Steel structures2010T.Vran, CTU in Prague18
