AbstractsEngineering

Note: Abstract listed in Table of Contents but absent from manuscript. The stability of girder webs has been under experimental observation since Fairbairn and Hodgkinson (1) made tests on models of the Britannia Bridge in 1846, and the theoretical aspects have begun to yield to mathematical treatment since G. H. Bryan (2) offered the first solutions in 1894. Nevertheless, forty years later, even so renowned an investigator as Timoshenko (3) stated at a Joint meeting of the AISC and ASME in 1933 that the design of girders cannot be considered as settled. And today, the need for further study of the problem has never been so urgent, For now, the designer is being forced both by economic necessity and new structural demands to review the specifications governing the proportioning of girder webs. Considering, first, that the cost per pound of rolled steel has increased 25-50% and that of fabricated steel has risen 50-100% over their respective pre-war values, it is necessary to re-examine designs which ten years ago were safe but conservative to see if today they cannot be made safe and economical. Moreover, in addition to these purely economic factors calling for a fresh approach to girder design, the public is demanding a more esthetic appearance in its new structures, such as, bridges. Taking the arch form as a criterion of accepted taste in these matters, the structure that lends itself most easily to that shape is the deep plate girder.[...]