Open Discussion on Anything you can do?... Towards a More Efficient Industry by S.B. Tietz

In the United Kingdom most highway bridges go to tender with a fully detailed design, bill of quantities, and specification. Alternative designs are permitted but, with the limited tender periods and the complications of the independent structural check recommended by the Merrison Committee and required by the Department, these are rarely offered by tenderers. However, some contractors have advocated the adoption of continental contractural methods. Design and build tendering was adopted for the Kessock Bridge only because tender prices-firstly for foundations and secondly for the whole bridge-greatly exceeded the estimates.

Mr. Tutt reported that further results were now available. These were for 215 mm thick walls, similar in size and shape to those already reported, and for 'C' shape walls, i.e. walls supported on both horizontal edge and one vertical edge. These new results are given in Table 1.

In this paper some important conclusions are drawn from a limited number of 1/3 scale tests. Some of these are dependent on the use of a scale factor, which the authors took as ƒA = 1.2 when comparing their test results on a 62 mm thick model with calculations of shear capacity to CP 1 10. This should be 1.3 for 150 mm slabs according to Table 14 in the February 1976 Amendment to CP 110. Furthermore, this table is applicable only to the practical range of slab thickness down to 150 mm. The relevant scale law from beam test results (4ah) would indicate that a ƒA value of 1.5 is appropriate for 62 mm slabs. Thus the 25% increase in ultimate shear stress proposed in the paper corresponds to the effect of neglecting the scale factor difference between 62 mm and 150 mm slabs. S.G.S. Feneron The importance of the slab/column connection