The Hanging Escalators of the London Underwriting Centre

Weight of a bath The recent correspondence on baths (July and September, 1994) has evidently generated wide interest, perhaps because a sudden wet and naked descent from bathroom to basement is particularly unpleasant to contemplate. Mr A. J. H. Davison warns of the dangers of giving generalised answers to specific problems: Might I venture to suggest that James Birdwood, in his response to the query raised by Morris Hill regarding the ability of a timber floor to support a fully loaded bath, would be less flippant if he were to look under any already installed bath and take note of the notched joists, anything up to one-third of their depth, to allow for the installation of pipes to serve the taps and waste. Verulam

The management of urban pollution in the UK has a long and successful history dating back to the 1840s when Sir Edwin Chadwick pioneered the separate collection of sewage and stormwater with the slogan ‘the rain to the river and the sewage to the soil’. At no time since then, however, has the pace of change and development been so great as it is today. Increased awareness of the importance of the environment and changes in public attitudes to pollution have been mirrored in the updating and strengthening of environmental legislation, which in turn has influenced the technical solutions required to solve pollution problems. Despite having a generally good-quality aquatic and marine environment, the UK is not without its pollution problems. Particular areas of concern are sewage treatment works (STW) effluents, combined sewer overflow (CSO) discharges and malfunctioning sea outfalls. David Butler

A numerical technique based on the theory of plasticity is presented to predict an upper bound on the collapse load of reinforced concrete beams in shear. The materials are assumed rigid-perfectly plastic. Modified Coulomb failure criteria with tension cut-of are adopted to predict yielding of concrete. A collapse mode is assumed, with rigid moving blocks separated by narrow zones of displacement discontinuity. The shape of yield lines and displacements of concrete rigid blocks are the variables involved in the energy equation. Minimisation of the predicted collapse load produces the optimum shupe of the yield lines. Examples of comparison with other upper-bound analysis and with experiment are given to show the applicability of this numerical technique to a wide range of problems. A.F. Ashour and C.T. Morley