I would like a better explanation of the jacking of the cable saddles on top of the bridge towers. The cable saddles are on sliding bearings and presumably were preset away from their final position deliberately, so that, when the cables were installed, the saddle would move into its direct location. Was the saddle jacking used to control this process or to actually induce stresses into new suspension cables?
Design of flat slabs is usually based on separate considerutions of flexure and shear, with empirical rules similar to those used in design of beams and continuous slabs. Additionally, shear capacity of a flat slab has to account for its distinctive mode of failure known as 'punching failure' or breaking away of a portion surrounding the column from the rest of the slab. Provision against such failure is often the critical design requirement for flat slabs with or without openings adjacent to the columns. While links are normally provided to enhance the punching shear capacity, the current Codes of Practice stipulate limits on the loadcarrying capacity of flat slabs. Such limits govern the thickness of the slab and, therefore, have a direct influence on economy of construction. This paper examines the limits on loadcarrying capacity of flat slabs supported on internal and rectangular columns, which are given in BS 8110 and Eurocode EC 2, with the help of tests on slab specimens with and without openings. S.B. Desai
People swinging from ropes has again become a common site in London. They are not unsuccessful members of the criminal community, but engineers, surveyors, painters, and glaziers. Industrial roped access techniques are now clearly recognised as useful tools in the construction industry. Andy Fewtrell
Britannia is a large North Sea gasfield. Its successful development was dependent on the project being executed within challenging budget controls. To promote this the project was carried out as an alliance between clients and contractors where rewards were dependent on total project cost and performance. The aim was to align client and contractor skills towards the common goals of creating safe and quality facilities, below cost targets, sharing the profits of success. C. Blow, M.A/ O'Donnell, R.M. Hodges and I. Wright
The environmental benefits of using waste materials in construction was identified as long ago as 1974. This paper describes the results of a project undertaken for the Department of the Environment, Transport & the Regions in which methods of utilising waste materials as alternative aggregates in structural concrete were explored. Three types of waste material were identified as potential aggregates: china clay waste, slate waste, and pulverised-fuel ash. IThe project investigated methods of utilising these materials as aggregate by low-cost processing and/or novel mix design. The results of the project were encouraging, since good quality concrete mixes were produced fron all three waste materials. A.K. Butler, D.S. Leek and R.A. Johnson
Reinforcement Detailing to BS 8666 This has raised a barrage of further comment. Rob Walker, a detailer with long experience, writes from Milton Keynes: I am but a poor draughtsman but, after reading your recent column with letters from your members regarding this new BS, I felt I had to make comment. Whilst in principle I do agree with your writers, Mr Holloway’s comments regarding shape code 51 show that he does not have a very high opinion of the intelligence of detailers and perhaps he didn’t realise that the drawing in the code is only diagrammatic.