The Cruachan Viaduct, Loch Awe

The duties and responsibilities associated with Building Regulations continue to stimulate what is, we are sure, a most useful and interesting discussion. Mr. F. D. Entwisle added to his succinct contribution (October 75) a further commentary stimulated by the observation of Mr. R. E. Musson and ourselves: I would like to comment on Mr. R. E. Musson's contribution and the last paragraph of your observations (October 75). Verulam

Effects of geometric imperfections in the form of the meridians of hyperboloidal cooling towers are re-assessed. It is shown that even moderate imperfections induce hoop stresses in the vicinity of the imperfection that are of the same order of magnitude as the meridional stresses that would occur in this same area of the perfect shell. K.O. Kemp and J.G.A. Croll

For some years, research has been carried out at the Cement and Concrete Association to study the relative structural merits of different reinforcement arrangements for certain common situations in reinforced concrete structures. This work was started partly because a few failures had occurred in practice and partly because there was a lack of basic data on how detailing affected strength. Early projects were therefore concerned with specific areas where problems had been experienced either in practice or in previous research projects and were aimed at determining the optimum steel arrangement purely in terms of strength. Topics covered at this stage included half-joints, flexural corners and compression splices in columns; the structural efficiencies of these were reported in a previous paper presented to this Institution'. H.P.J. Taylor and J.L. Clarke