Overall Stability of Structures

It seems possible that BS449 is beginning to displace CP110 as a subject for comment to this column. Our old friend Mr. Hairsine writes : I should like to draw members' attention to a recent amendment to BS449 (Amendment No. 5: AMD 1787) which quietly introduces changes affecting the design of bolted connections and web buckling calculations. Verulam

The paper describes how various factors peculiar to the site together with a desire to impose maximum design and construction standardization led to the use of precast MOT/C&CA prestressed concrete M beams for the decks of a large multi-viaduct interchange at the London end of the M11 motorway. B.P. Pritchard

Introduction by Dr. Taylor: Four years ago, to this month, a paper of which I was a joint author (with Dr. Somerville) entitled 'The influence of detailing on the strength of reinforced concrete structures' was presented to this Institution. At the close of that paper, Mr. Geddes, then President, suggested that the Institution would like to hear more of our continuing research on detailing. Although this paper treats some more detailing problems in much the same way as before (and in one case presents more information on a subject discussed before) our approach to detailing problems has been extended. The basic message from our previous paper was that the normal Code rules for detailing (bond, bearing etc.) are not necessarily sufficient when considering the detailing of critical parts of concrete structures, in particular at intersections between elements. In the cases mentioned in the last paper it was suggested that, providing internal statically determinate truss systems could be envisaged and steel was provided to carry the tension, with concrete carrying the compression, the resulting details would have a good chance of working safely.