South African civil engineers are justifiably proud of their loading code. Thanks to work carried out in the 1980s, the code is theoretically sound and lays a solid platform for the development of materials codes. Regrettably, the development of materials codes has not been pursued. We have elected instead to adopt overseas codes and adapt these to local conditions. Our concrete code, for example, is modelled on British practice and our steel code on the Canadian approach.
The history of the South African loading code (The general procedures and loadings to be adopted in the design of buildings: SABS 0160: 1989) started in 1983 when a working group was established by the Structural Division of SAICE to make recommendations on appropriate policy for the formulation of limit-states requirements in South African structural codes. The working group agreed at an early stage that, from the point of view of logic, consistency and convenience, the partial load factors and load combinations applicable to all materials in building structures should be defined in a revised South African loading code.
Current code approaches for overhead cranes South Africa The current South African loading code, SABS 0162: 1989 (Code of Practice for the general procedures and loadings to be adopted in the design of buildings). defines four classes of crane, based on the type of usage for which the crane is intended. The highest and lowest of these are defined in Table 1. The loads induced at each wheel by the action of the crane are then defined as impact factors multiplied by relevant static loads. These are also given in Table 1.
Wind load is a statistical quantity and the design codes of various countries have developed individual systems to represent its load effects. The stipulations included in the current South African loading code (SABS 0160-1989) are based on the old British Code (CP3 1952) and on research by Dr Milford.
Can engineers continue to ignore or abdicate their socio-economic responsibilities? Richard Maasdorp considered the situation in an article printed in 'The Zimbabwe Engineer' early last year. In my view, engineers in Zimbabwe continue to hold onto traditional conditions of tender and adjudication as a convenient barrier against change. They pontificate thus: * We must uphold the tender procedure * Price carries the greatest weight * Politics and engineering should not be mixed * If we are given new rules of affirmative action parameters, we will reluctantly adhere to them but when contracts go wrong/late we will say 'I told you so'
Graham Ross, the compiler of this series, comments: Henry Lichtenstein had a few remarks in 1803, when faced with Kaaiman's Cleft near Wilderness: ' ... the monstrous gulph is now directly beneath, and at the depth of a thousand feet the torrent roars over its stony bed ... after having crossed the stream, ascends again a height, which ... I will not say appeared exceedingly steep, it actually appeared perpendicular .. .' At the age of 16 Pieter Baartman joined the provincial construction unit in George in 1945.
The natural environment has caused contractors to take great care on this Cape contract The South Peninsula Municipality gave the go-ahead last year to fund and provide access to a number of plots perched on an almost sheer mountain slope high above False Bay, beyond the end of Echo Road in Fish Hoek. This decision will enable owners to develop and build on sites that command incomparable views over False Bay. The extreme costs associated with both site development and house construction will undoubtedly ensure their exclusivity.
Approaches to stream bank restoration, flood control and wetland works have changed dramatically. 'It's not just concrete trapezoidals anymore: said Robbin Sotir of Robbin Sotir & Associates, Atlanta, whose firm has been doing bioengineering - using vegetation for stabilisation purposes and for wetland creation - for 20 years. The American Society of Civil Engineers (ASCE) took the lead in organising the Wetlands and River Restoration Conference last year in an effort to enhance communication between disciplines. The conference consensus was that engineers, scientists and contractors have to learn to work together in a different way.
The paper gives an account of the first modern mechanically aerated activated sludge sewage treatment plant in South Africa. Economic aspects of this type of treatment are descriptionbed, and design and performance data for the first year of operation are given. A descriptionption of oxygenation capacity tests conducted prior to the commissioning of the plant is included.
The paper gave data on the South African road system, the vehicles using it and the amount of money spent on it. Estimates of the annual mileage travelled on all urban and rural roads were given. Comparisons were made of the South African accident rates with those of some other countries, indicating a particularly high fatality rate in this country.