Riyadh Conference Centre and Hotel

Mr. J. A. Baird has written in amplification of his earlier letter which appeared in this column in September 1975: Somehow my edited contribution on training and engineer's failures has been misunderstood (The Structural Engineer, Vol. 53, No. 9, p. 400). Mistakes are being made and of course they have to be investigated, preferably by someone experienced, perhaps even specializing full time in such work. However, my communication was to draw attention to the appointment made necessary because we, as a profession, are making sufficient errors for a fulltime inspector to be required, and to ask if we are satisfied with current training which has led to this situation. Verulam

A social involvement The title of my address, 'The structural engineer's significance', is not only provocative, as intended, but is clearly incomplete and poses the obvious question: significant in what respect? To answer the question there are a number of expressions which come to mind: with regard to society; to engineering (and it would be interesting to know what would be the order of preference given these two by most members of this Institution); to the sciences: to the quality of life; to the economy? And there are a number of others. If indeed, we should vary the title by calling it 'The structural engineer's contribution', to the foregoing rather general areas of interest we can add more specific ones, for example: the multidisciplinary team; his own and other professional bodies and institutions; the cityscape. (I have had to coin this word because I could not find one that conveyed what I meant- 'seascape' and 'landscape' are clear enough to everyone but how else could one say, in a word, that one meant the visual impact of the large built-up area?). Peter Mason

The opening section of the clause on design in the Code of Practice for concrete reads: 'The purpose of design is the achievement of acceptable probabilities that the structure being designed will not become unfit for the use for which it is required.. . ' The clause goes on to refer to variations in loading and in the properties of materials used; it mentions the need for statistical data on these variations and introduces the partial safety factors necessary to achieve this design objective. It does not, however, define the acceptable probability of a structure becoming unfit for use which is basic to the design concept. At present this is not possible in quantitative terms and may never become so; it can however be stated qualitatively after appraisal whether individual structural failures or cases of unserviceability are acceptable or not. Experience shows that structural inadequacy is seldom due to a single cause; it is often the result of a combination of effects, which may include overloading, fire, impact or explosion, settlement, design errors and faults in construction. Of these, faults in construction have played a major contributory part in causing failure, as illustrated by a few examples drawn from the building field: