Advisory Desk / Codes and Standards / 50 Years Ago
AD 420: Minimum values of shear and bending
moment in beams with web openings
Table 3.1 of SCI publication P355 gives minimum
values of co-existent shear and bending moment
to be used at beam openings. This AD provides
clarity on how these minimum values are to be
used.
The concern behind the minimum values was to
allow for non-uniform loading, to guard against the
situation when the shear force at an opening could
30 NSC
July/Aug 18
theoretically be zero. Table 3.1 therefore includes
minimum values of the shear force to be allowed
for in design. The minimum values of shear force in
Table 3.1 have an associated bending moment.
The intention was that the minimum shear force
and associated bending moment from Table 3.1
should only be applied if the theoretical shear at an
opening was less than the minimum quoted. There
is no requirement to apply the minimum bending
moment at all openings – the minimum bending
moment should only be applied if the minimum
shear force is used in design.
Contact: Prof Mark Lawson
Tel: 01344 636555
Email: advisory@steel-sci.com
BS EN PUBLICATIONS
BS EN 1011-8:2018
Welding. Recommendations for welding of
metallic materials. Welding of cast irons
Supersedes BS EN 1011-8:2004
CORRIGENDA TO BRITISH STANDARDS
BS EN 10219-1:2006
Cold formed welded structural hollow sections of
non-alloy and fine grain steels. Technical delivery
requirements
Corrigendum, April 2018
BS EN 10219-2:2006
Cold formed welded structural hollow sections
of non-alloy and fine grain steels. Tolerances,
dimensions and sectional properties
Corrigendum, April 2018
DRAFT BRITISH STANDARDS FOR PUBLIC
COMMENT - ADOPTIONS
18/30336161 DC
BS ISO 6930 High yield strength steel plates and
wide flats for cold forming. Delivery conditions
Comments for the above document were required by
7 June, 2018
CEN EUROPEAN STANDARDS
EN 287-6:2018
Qualification test of welders. Fusion welding. Cast
irons
EN 14399-9:2018
High-strength structural bolting assemblies for
preloading. System HR or HV. Direct tension
indicators for bolt and nut assemblies
EN 14399-10:2018
High-strength structural bolting assemblies for
preloading. System HRC. Bolt and nut assemblies
with calibrated preload.
The West Central District Office, Holborn,
London, and the Postal and Sorting
Office in Whitechapel Road, London
The West Central District and
Eastern District Offices are large
multi-storey projects for the
mechanised handling and sorting of
general letter and parcel mail. These
offices require large basic grids and
have storey heights much greater
than normal offices. Likewise, there
are the same requirements for
future adaptability and modification.
The basic grids are 40 ft by 32 ft and
47 ft by 47 ft respectively.
Mainly because of an insufficiency
of repetition and irregular
plan configuration, lightweight
aggregate precast concrete floor
panels have not been used on these
projects. Instead both have the
major basic skeleton in steelwork,
with secondary beams and floor slab
in in situ reinforced concrete, the
two elements acting compositely.
This produces a waffle like grid
which means that the slabs and
their supporting beams span in both
directions. Hence, the floor slabs are
relatively thin, and because of the
two-way span system can tolerate
quite large holes being cut through
in the future. The two-way system
reduces overall floor and beam
depth. The use of steel for the main
skeleton minimises the overall
dimensions of the main stanchions,
and reduces dead loads.
It is of interest to note that at W.C.
District Office (pictured) two lines
of stanchions were eliminated
between ground and first floor to
provide clear areas for vehicles
between the loading platforms. This
was achieved by the introduction
of twin welded plate girders in B.S.
968 steel spanning 65 ft, each pair
supporting an upper stanchion at
mid span carrying approximately
850 tons. The senior architect
for these two projects was E.T.
Sargeant, ARIBA, AMPTI, and the
Senior Structural Engineer was R.
C. Westbrook, MIStructE.
To read about the W.C. District Office’s latest
incarnation, see ‘In the post’, NSC March 2018
New and revised codes & standards
From BSI Updates June 2018
Reprinted from Volume 5 No. 2
June 1968
General Post Office
Expansion and
Composite Construction
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