Author: Thompson, P W;Yates, A S
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Thompson, P W;Yates, A S
The Structural Engineer, Volume 72, Issue 12, 1994
Recommended foundation depths in shrinkable clays A letter from Mr G. A. H. Trollope on 18 January questioned the adequacy of a BRE recommendation on minimum foundation depths on sites without trees in that it did not, in his opinion, allow sufficiently for problems possibly arising because of newly planted trees over the likely lifetime of the property. Letters on 15 March from Richard Driscoll of BRE and from Mr J. S. Tari challenged the practicability of such a requirement, but Mr Trollope received support in his contention from Mr R. E. Hedges (19 April) in that owners, ignorant of the factors involved, would inevitably be very likely to plant trees that could cause trouble. The argument is pursued further by Stan Lawrence, from Brighton, who offers a possible means of overcoming the dilemma: Mr Driscoll and Mr Tari have both presented sound cases proving how uneconomical and unreasonable it would be to introduce the suggested ‘ideal’ proposals of Mr Trollope and Mr Hedges which ensured that all buildings built on shrinkable clays would never be damaged by foundation problems relating to adjacent trees. Verulam
Results are presented of tests on 10 transverse strips of reinforced concrete voided slabs subjected to transverse shear. The need for web reinforcement to control diagonal cracks is demonstrated. The failure loads and modes of the strips are compared with those predicted by a proposed theory and reasonable agreement obtained. In addition, reasonable agreement is obtained between the theory and independent test data. Finally design and assessment procedures are suggested. Professor L.A. Clark and P. Thorogood
Mr Peter Campbell (Past President) You have rightly drawn attention to the enthusiasm and dedication of all the people involved that produced a fine solution to the problem, but I suspect that the client had a special role in this particular project. All too frequently the client is a remote person who contributes very little, and I suspect that Stuart Lipton and his team played a very major role in the whole thing. Could you tell us a little more about the actual way in which they did contribute, and perhaps the drive they engendered in the whole of the design process that resulted in the adopted solution.