A method is presented for estimating automatically the ultimate strength of pin-join ted triangulated structures. The method is based on the principal assumption that individual members can resist a constant load affer buckling or after yielding in tension and it has been incorporated into a computer program. Professor Y.K. Shin
Mr. R. A. D. Noble: ‘In their paper Bobrowski and Bardhan-Roy put forward a simple empirical method for calculating the ultimate strength of reinforced and prestressed concrete beams in combined flexure and shear which applies equally to rectangular and I sections. The treatment of the test results in this paper leads me to the conclusion that the actual thickness of the web in prestressed I beams does not play such a significant part in determining the actual ultimate strength in combined flexure and shear as it would appear to do either in existing design practice based on principal tensile stresses, or in new proposals for the Unified Concrete Code. It is of particular interest that some of the data is taken from tests at elevated temperatures under exposure to fire, since recent proposals by the FIP, which are likely to be adopted in this country, recommend limitations to the thickness and slenderness of webs in this context. In view of the material presented in this paper it seems to me that these proposals might be unnecessarily restrictive.
Professor Arthur Bolton, Dr. I.D. Armstrong and Mr. J.F. Doyle: ‘Referring to the derivation of S we feel that the expression has an error resulting from a simple oversight.'
Some cases where incorrect design of beams supporting two-way slabs may result from the use of only the triangular and trapezoidal load distributions which follow the shape of the segments of the panel collapse mechanisms are described and discussed. R. Park
The paper describes the main features of the design and construction of three 74-storey blocks of flats for the Royal Burgh of Ayr in the Bison Wall Frame System, an industrialised load-bearing wall system using large floor and wall panels of precast concrete. D.H. Orme and S. Thorburn
As is customary at the first Ordinary Meeting of the New Year, the meeting of the Institution at 6 o’clock on Thursday 8 January 1970 will take the form of an open discussion. This year’s theme is the economic consequences of substantial claims-a subject of importance to all engineers and indeed to all in the construction industry. All members are invited to bring to the meeting, colleagues from the contracting industry from whom contributions to the discussion will be most welcome.