Cements with Controlled Expansions and their Applications to Pre-stressed Concrete. Discussion on M.

The application of electric arc welding to the fabrication of steel bridge girders and building frames has resulted naturally in the increased use of the “continuous” or “rigid frame” type of structure. Typical of this form of construction are the portal frame and Vierendeel girders, for both of which satisfactory methods of computing the member moments, loads and shears have been evolved. An examination of the literature, however, shows that reliable methods of designing the joints between the members of these structures are less well known and that there is some doubt as to the degree of accuracy with which the stresses in the joints can be estimated by such formulae as have been put forward. Arnold William Hendry

This month's letters include discussion over design checks and suitably experienced engineers as well as seismic design of masonry and more.

The tragedy of the Francis Scott Key Bridge highlights the need for structural engineers to ensure that the risks inherent in our built infrastructure remain acceptable, argues Colin Caprani.