Joints - The Behaviour and Design of Steel Structures to EC3 - page 407

Load-bearing
stiffener

Column

N Ed

Base plate

Beam

R Ed V Ed

Seating plate

Holding-down bolts

Anchor bolts

(a) Beam seat (b) Column base plate

Figure 9.17 Common beam seat and column base plate arrangements.

aflexibleendplateconnectiondesignedinaccordancewithEC3-1-8aregivenin
Section 9.10.

9.5.2 Angle seat joint

An angle seat joint (Figure 9.14a) transfers a beam reaction force R Ed to the
supporting member through the angle seat. The top cleat is for lateral restraint
only,andmaybeboltedeithertothetopofthewebortothetopflange.Theangle
seat may be bolted or fillet welded to the supporting member. The joint has very
little moment capacity, and is classified as a nominally pinned joint. It may be
used for simple construction.
Thebeamreactionistransferredbybearing,shear,andbendingofthehorizon-
tal leg of the angle, by vertical shear through the connectors, and by horizontal
forces in the connectors and between the vertical leg and the supporting member.
In this joint, the beam is designed for zero end moment, and the supporting
memberfortheeccentricbeamreaction.Thebeamwebmayneedtobestiffenedto
resistshear(Section4.7.4)andbearing(Section4.7.6).Althoughthisjointiseasily
designed, its use is often discouraged because of erection difficulties associated
with the close depth tolerances required at the top and bottom of the beam.

9.5.3 Flexible end plate joint

Aflexible end plate joint (Figures 9.6a and 9.14b) also transfers a beam reaction
R Ed to the supporting member. The end plate is fillet welded to the beam web,
and bolted to the supporting member. The flanges may be notched or coped, if
required.Thisjointalsohasverylittlemomentcapacity,astheremaybesignificant
flexibilityintheendplate,andisclassifiedasanominallypinnedjoint.Itmaybe
used for simple construction.