The Structural Engineer in the Coal Industry

THE PRESIDENT, proposing a vote of thanks to Dr. Collins, said that, as stated in the paper, research on a scale such as he had discussed could not be described adequately unless only a certain short term of years was covered at a time, and it would be agreed that he had dealt with it adequately in this paper.

Structural research at the Building Research Station is aimed partly at extending the general body of structural theory and partly at codifying this general body of theory into Codes of Practice and similar Standards. Some programmes are undertaken specifically to help in the redrafting of a particular Code. A recent example has been a series of tests designed to check one of the revisions in the latest issue of B.S.449, 'The use of Structural Steel in Building.' This relates to the load-carrying capacity of concrete encased steel stanchions subjected to axial and eccentric loading. In the 1948 edition of the Standard, the only structural benefit the designer could derive from such encasement was a reduction in the assumed slenderness ratio of the stanchion due to the stiffening effect of the concrete. It has been shown that such stanchions can in fact be safely treated as composite sections in which a proportion of the direct load is carried by the concrete, acting at a stress of one thirtieth of that in the steel. In the latest version of the Standard, design on this basis is allowed with the proviso that the working load shall not exceed twice that of the corresponding bare steel stanchion. This can result in savings of up to 30 per cent in the weight of steel section required.

Discussion on the following papers:- (1) Application of an Electronic Digital Computer to Structural Steel Design, by L. Morgan. (2) The Analysis of Grid Frameworks and Floor Systems by the Electronic Computer, by E.Lightfoot, M.Sc. (Eng.) , Ph.D., M.I.Struct.E., A.M.I.C.E. (Delegate Member of Council)and F. Sawko, B.Sc. (3) Elastic Critical Loads of Multi-bay Pitched Roof Portal Frames with Rigid External Stanchions, by D. M. Brotton, B.Sc., Ph.D., A.M.I.Struct.E. THE CHAIRMAN proposed a hearty vote of thanks to the authors for the considerable amount of work they had put into the preparation of their papers and for the way in which they had presented them.