Issue 14

The paper presents the results of fire tests on eight beam-to-column connections, typical of those used in modern framed buildings. Five tests were on non-composite beams, two on composite beams,and one on a shelf angle floor beam. Both protected and unprotected members were included. The tests demonstrated the ‘robustness’ of these connections in fire and showed that signifcant moments (up to two-thirds of their design moment capacity) could be sustained in fire conditions. R.M. Lawson

Mr A. N. Beal (M) (Thomason Partnership) There is a strong need to develop buckling analyses for columns of non-linear materials - not only for the hot-rolled stainless steel considered in the paper but also for reinforced concrete, plain concrete, timber, and masonry.

A timber bridge guardrail specimen, subjected to static loads, was mathematically modelled as a beam on coupled, elastic supports. The spring coupling was provided by the bridge deck structure to which the line of guardrail posts was attached. The spring stiffnesses used as input to the model were determined experimentally by transversely loading each post of a timber guardrail section of a longitudinal laminated deck bridge after the guardrail member was removed. Using these stiffnesses, the model was executed to predict the deflections of the reassembled guardrail system. The model proved to be a good predictor of both rail-displaced shape and magnitude of deflection. Superiority of the coupled spring model over a similar model assuming independence (uncoupled springs) of posts in the system was demonstrated. P.J. Pellicane, Professor R.M. Gutkowski and M.S. Malone

The Institution’s History Group has made two study visits to Paris, one in the summer of 1986 and one last summer. To record all the structures visited, the archives inspected, and the lectures given for us, would take many pages. However, as a foil to the Group’s current exhibition at the RIBA Heinz Gallery on the impact of structural iron on architecture in Britain, it may be interesting to look at iron in the same context in France during the same period, essentially in relation to what we saw. Nearly all the iron structures which we studied in Paris-mostly buildings rather than bridges-date from the same period as those in the exhibition, i.e. 1780-1880. R.J.M. Sutherland

Foundations of buildings near trees The above topic, raised in our column for 21 November last year and aired again in January and March this year, has attracted further comment from Mr Z. Przygoda, in Don Mills, Ontario, Canada: I have read with interest the many comments about trees and how they affect the foundations of buildings. This is an important part of structural design. Verulam