The Chairman opened the discussion by bringing in a point not emphasized in the paper-that so much largescale prefabricated building using big units had become possible, in his opinion, because of the remarkable development in crane building in the last 20 years. As the author had said in his introduction, industrialized building was nothing very new. In the early 1930s a lot of prefabricated buildings had been designed, but the cranes available were so limited that advantage could not be taken of large units.
Dr. H.J H. Starks (Road Research Laboratory) said that those present had listened to a most interesting lecture, from which they had seen how the engineer and the surgeon acted together as a team to solve a variety of problems concerned with the alleviation of suffering and with fundamental knowledge of the body as a physical structure.
Mr. M. E. Richards writes:- ‘The author states in this paper that this method of analysis is not taught in Britain. I should like to point out that numerical methods of volume integration are now being taught at Korthampton College of Advanced Technology, London to civil engineering students.'
This paper describes the behaviour of seventeen simply supported composite T-beams under static concentrated and distributed loading applied on the axis of the beam. The amount of shear connexion (welded studs) was varied within the range which might be contemplated for design purposes and the effect of interface slip on elastic and ultimate load behaviour was observed. Recommendations are made concerning design of the beam section and of the shear connectors. The use of ultimate load design for the composite section may lead to working stresses approaching the yield stress, because of the large shape factor. It is suggested that, notwithstanding the method used for designing the section, the shear connexion should be designed to carry the horizontal shear force existing in the beam at ultimate load. For this purpose it is recommended that 80 per cent of the experimentally determined ultimate capacity of the shear connectors should be used. In the case of uniformly loaded beams, a uniform spacing of shear connectors is satisfactory, notwithstanding the triangular distribution of the external shear force. J.C. Chapman and S. Balakrishnan
This paper sets out to describe two railway bridges which have recently been reconstructed with composite steel and concrete superstructures. Brief details are given of the history of the old structures now replaced, together with alternative schemes which were considered in the design stage. Methods of construction whilst maintaining rail traffic are discussed and general conclusions regarding the use of composite construction for railway bridges are drawn from the experience of these two cases. C.F. Bonnett