Soil Buckling and the Leaning Instability of Tall Structures

Microcomputers It is now nearly a year since Mr B. C. Bird asked his question about frame analysis programs for the 48K Spectrum. Since then we have had a substantial response from our readers, drawing attention to programs and problems associated with their use. This month we have three more letters. Mr K. Tregear, writing from Nizwa in the Sultanate of Oman, says that he was most interested to read, in the December issue, of the approach by Mr Bradfeld to the design of rectangular beams and slabs in accordance with the CP 110 idealised stress block.

The paper describes the development of the design of Kylesku Bridge as a sequence of design studies and decisions, from studies of the location of the new bridge and of different types of structure to final design. The new bridge is a frame with V-shaped supports. It is built in concrete and the deck is a box girder that is prestressed. The bridge was designed to be built in stages and within constraints that were specified in the contract documents. J. Nissen, K. Falbe-Hansen and H.S. Stears

This paper describes research on dynamic behaviour of conveyances and mineshaft steelwork. A description is given of the system used for measuring and analysing accelerations and wheel loads in 13 shafts, as well as the simplified theoretical model developed for predicting this behaviour. Results are given of both the measurements and the theoretical predictions, and the relevance of different design parameters is discussed. A tentative design formulation is proposed which includes the most important variables for shafts where resonance does not occur. Factors influencing dynamic magnification are also discussed. G.J. Krige, Professor A.R. Kemp, B. Alport and M. Fotopoulos