Flange splice

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Chapter 11

• Flange splice

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Introduction In shop, flanges shall be joined by
complete penetration but welds, where possible.
These welds shall develop the full strength of
the plates. The flange plate can be obtained in
length up to 15 m and thus in plate girder over
15 m span we have to arrange field splice at
which the web plate and the flange plates are
cut. Flange joints should not be preferably
located at points of maximum stresses. Where
splice plates are used, their area shall be not
less than 5 in excess of the flange plate.
There shall be enough bolts on each side of the
splice to develop the maximum strength of the
flange plate.
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One splice plate covers the joint of the flange
or splice plates on both sides of the flange
plate may be used. For example if we have flange
plate 320?20 mm we can use one splice plate
320?(20 22) mm.
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-   Net area of flange plate (32 - 4?2.4) ?2
44.80 cm2. -         Number of bolts (for one
side), (single shear field bolts, M22, Q8.8)
n ? n qb 0.25 Fub 0.25?8 2 t/cm2 Rs.
sh qb ?As ?n 2?3.03?1 6.06 t (n No. of
shear planes) ?y 3.6 t/cm2 (St 52) ? n Use
20 bolts (4?5)
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Or we can use One splice plate 320?12 mm from the
outside and two splice plate 120?12 mm from the
inside of the flange plate
-         Net area of splice plates -        
(32?1.2 2?12?1.2) ?2 - 2?2?1.2?2.4 67.20
11.52 55.68 cm2. -         Number of bolts
(double shear or bearing field bolts, M22, Q8.8)
n ? n
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qb 0.25 Fub 0.25?8 2 t/cm2 Rd. sh qb
?As ?n 2?2?3.03?1 12.12 t (n No. of shear
planes) Rb Fb ? d ? min? t Fb ? ? Fub ?
depends on end distance (S), (Table 6.2)
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?3d
?2.5d
?2 d
?1.5d
?
Edge distance 2.5 ? ? ? 1.0 ? Fb 1.0? Fub
8.00 t/ cm2 Rb 8.0 ? 2.2 ? 2.0 35 t
Back
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?y 3.6 t/cm2 (St 52) ? n Use 10 bolts (2?5)