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