An attempt is made in this paper to summarise the behaviour of a range of shear wall systems, starting from an elementary planar shear wall to a complex arrangement of core systems. Emphasis is placed on the structural interaction that exists between the walls and floor system. Significance of non-uniform torsion theory as applied to open core structures is explained with a practical example problem. A two-step procedure is presented for a comprehensive analysis of complex shear wall buildings; one for evaluating the structural contribution of the out-of-plane stiffness of the floor system and the other for a 3-dimensional analysis in which open core structures are modelled as equivalent columns. B.S. Taranath
Mr A. Edwards (Higgs & Hill): As a non-member of the Institution I found this paper exceptionally readable and comprehensive, and I would congratulate the authors on giving such a clear picture of the development of the project and of its complexity.
At a recent conference on the subject of ‘Durability and design life’, opinion was divided as to whether it would be possible to define ‘design life’ and designate appropriate periods, and, if so, whether it would serve a useful purpose. The reasoning for establishing the intended design life of any particular structure is put forward here. G.E. Bratchell
The paper reviews the worh of Paul Cottancin, a French structural engineer working at the turn of the century. The Cottancin system of reinforced concrete, which is based on the use of woven wire placed in relatively thin concrete sections, is described, us is his use of reinforcement in both brickwork and glass. A list of buildings and structures for which Cottancin acted us engineer is given, and five of these are described in some detail. It is concluded thut greater study of the history of structural engineering by engineers would be unlikely to ,familiarise them with the work of Cottancin; also that, although some of his ideas are highly unusual, the concepts he used regularly (e.g. deep beam action, wall-floor combined action) are less well used today than they could be. G.J. Edgell
CP 110 and its shortcuts Suggestions and proposals -for simplifying the methods of design recommended in CP 110 occur fairly frequently in this column. We were prompted to look at some of the earlier references and found them in issues which included August 1982, January 1983, January 1984, October 1984, and January 1985. We have now received a further contribution from Mr P. E. Wheatley of Easterton, Wiltshire, who draws our attention to another proposal. Verulam