I dedicate this article to Sam Amod Pr Eng and Peter Kleynhans Pr Eng, who in the past three weeks, while working on a sensitive project of national importance, impressed upon me the meaning of Civil Engineer. I have had the pleasant experience of meeting the late Eric Hall - former City Engineer of Johannesburg, Honorary Fellow of SAICE, recipient of SAICE's prestigious Gold Medal, and SAICE President in 1973. A famous story of Eric Hall's is, when asked what he would have been had he not been a civil engineer, he responded, "... ashamed of myself!"
The South African National Roads Agency SOC Limited (SANRAL) is known for demanding only the best from the country's road-building fraternity. This is exactly the case with the rehabilitation of the N1 section from Sydenham (km 28.8) to Glen Lyon (km 62.4) near Bloemfontein in the Free State. When completed in May 2017, this road will have a life of up to 20 years, mirroring innovative design characteristics and outstanding workmanship. Johan Acron, project manager at Raubex Construction, Africa's largest road builder, says the high-level design specifications for this road makes it one of South Africa's many flagship projects in terms of road rehabilitation works. Designed by consulting engineering firm, Worley Parsons, the road is made up of 350 mm G4-stabilised sub-base, 120 mm bitumen-treated base (BTB) course and 20 mm ultra-thin friction course (UTFC).
At the second Civilution Congress, held on 9 and 10 May 2016 at the Gallagher Convention Centre in Midrand, leaders from across the engineering spectrum engaged in thought provoking discussions in line with the congress theme of accountability, which included matters such as ethics and delivering value for money. We will be sharing some of these presentations with our readers over the next few editions of Civil Engineering, commencing with a lightly edited version of Prof Mike Muller's address. (Prof Muller was Director-General of the Department of Water Affairs and Forestry from 1997 to 2005 and, while serving on the National Planning Commission, was part of the team who prepared the National Development Plan 2030.)
Accountability, the theme for this year's Civilution Congress, is a good one, as it allows us to:
do introspection, and
deal with the real issues affecting us
as young graduate engineers and upcoming professionals. The most important real issue that I would like to bring to your attention concerns engineering skills. Some time ago a few of my young colleagues and I were talking about the fact that very often we work till late at night with the aim of educating ourselves, because it is not easy to find mentors who have enough time to show us the ropes. The only way for us to gain a better understanding of what we are doing seems to be to put in extra time.
The electrification of urban areas in South Africa, including many informal settlements, reached its culmination during recent years. However, the electrification of rural areas still has a long way to go before most of the rural communities will be provided with a reliable and sustainable electricity supply. The national electricity grid, managed by the parastatal ESKOM, has been experiencing problems due to various reasons, particularly since 2008. The further development of rural electrification is currently on the back burner, mainly due to the shortage in the generation capacity available to ESKOM, which needs to be made available to the users already connected to the national grid. The increases in the price of electricity are starting to be felt by urban and rural communities alike. The primary electricity infrastructure (coal-fired power stations, major supply lines and distribution of electricity within urban areas) is rapidly becoming insufficient and cannot sustain a supply against the demand for electricity from the existing and future users connected to the national grid.
The Nooitgedagt Water Treatment Works (WTW) is at the heart of the Nooitgedagt/Coega Water Supply Scheme that provides potable water to the Nelson Mandela Bay Metropolitan (NMBM) area (Port Elizabeth, Motherwell, Uitenhage and Despatch) and the Coega IDZ. The scheme comprises high- and low-level systems with an approximately 90 m elevation difference between the two.
Many of South Africa's rivers, especially those flowing through urban areas, have been rendered unstable by ongoing - and often accelerating - development in their catchment areas. Under these conditions, careful rehabilitation and management of river systems is now vital to safeguard lives, property and public assets. In one such intervention, the City of Johannesburg (in conjunction with the implementing agent, the Johannesburg Roads Agency) has commissioned a study on the state of the city's longest river - the Braamfontein Spruit - to establish what needs to be done to improve the natural habitat and surrounding infrastructure. SRK Consulting Africa, who has applied its river engineering expertise to such projects in several water courses over the past decade, is conducting the study. Its practice and methodology is discussed here as a contribution to enhancing knowledge and building a more sustainable society.
Tailings dams store large volumes of mine tailings. It is generally assumed that strength gain in tailings is due to dissipation of excess pore pressures, although column experiments have shown that this process occurs very rapidly and that, after dissipation, the tailings are still weak. It is still not entirely understood how pore pressures change during normal deposition on a tailings dam.
Fifty years or so ago, the geosynthetic installation industry was in its infancy, and people were experimenting with materials and ways to join them. Just about anybody with a roll of plastic and a welding system could line a dam or toxic waste facility. How things have changed! Innovation upon innovation occurred, and it soon became evident that the highly engineered materials and installation demands required a significant degree of experience and expertise, combined with strict quality control.
South Africa celebrated National Water Week in March, with the theme Water for people - Water by people; Water has no substitute. In the spirit of this theme a South African company has developed a technique that provides a reliable water source by implementing a localised water treatment and supply system. Prentec (Pty) Ltd are the developers of the Aquastation technology, an off - grid system that provides water to rural communities and eco-tourist lodges which are far from reliable sources of water and power.
To counter vandalism, which robs owners of equipment worth hundreds of thousands of rands, pump stations are increasingly being built like fortresses, complete with thick reinforced concrete walls and roofs, and with small ventilation holes in the walls instead of windows or steel louvres, which are vulnerable to attack by angle grinders and oxy-acetylene torches. Consistent with these measures, the installation of self-supporting, heavy but easy-sliding 60 MP a concrete doors - SA Patent 2008/06587 - together with extremely robust locking mechanisms, are being specified more and more by consulting engineers. The concrete is completely immune to attack by oxy-acetylene torch, and the steel reinforcing in the doors is too dense for chisels to penetrate.
The American Society of Civil Engineers (ASCE) has a programme which declares a deserving prominent historic engineering project an International Historic Engineering Landmark. A potential such landmark has to be identified by the engineering institution of the host country, and is then subjected to rigorous examination by an ASCE panel to ascertain whether it meets certain key criteria before it can qualify for the award.
Ancient beginnings - the world's first lighthouse of any consequence was situated in Africa, but at the opposite end of the continent to the one we are celebrating. It was built on an island called Pharos at the entrance to the port of Alexandria in Egypt in 279 BC for King Ptolemy II. By any standards it was a giant - 140 metres tall on a base 33 metres square. The fire at the top could be seen over 40 km away. Quite rightly it became one of the Seven Wonders of the Ancient World. By comparison the Cape Hatteras Lighthouse on the coast of South Carolina, the tallest in the United States, is 60 metres high; the Skerryvore, pride of the British Isles, 48 metres; and the South African champion, Slangkop, a mere 33 metres. The designer and builder, Sostratus, must have known his trade. How he lifted the huge limestone blocks into position is a matter for speculation; he then 'cemented' them together with molten lead. Two thousand years later the same material was used in building the second Eddystone Lighthouse. The method was obviously successful, because the structure stood for 1 500 years - the tallest ever built until overtaken by the American skyscrapers in the 1930s.
The much vaunted South African National Development Plan (NDP) represents, without equal, the greatest opportunity for our beleaguered subcontinent's upliftment and long-term sustainability since the 1994 democratic election in South Africa. However, it could also remain a frustratingly distant and unreachable rolling horizon, or even become an extravagantly costly nightmare if the appropriate scarce and critical skills and knowledge crisis is not addressed effectively and timeously. The long-cherished traditional and theoretical models of teaching, learning and knowledge sharing, with an increasing focus and reliance on systems-oriented approaches to knowledge identification, gathering, capturing, packaging, sharing and transfer, have proven to be predictably ineffective and unsustainable - both locally and globally. This is true within almost every industry type and size, and it is certainly true within most engineering and construction organisations, which have the added complexity of highly mobile and remotely-situated staff who move nomadically from project to project.
The latest Biannual Economic and Capacity Survey of Consulting Engineers South Africa (CESA), for the period July to December 2015, indicates that times are tough and getting tougher, with industry confidence the lowest in 16 years. The report indicates that the consulting engineering industry will have to adapt to a low-growth environment, as the outlook for infrastructure spending is hampered by poor economic growth, lower than expected revenue by government, international economic instability and price volatility, and low private sector confidence. Over 540 firms employing just over 24 315 staff, who collectively earn a total fee income of R23.4 billion per annum, are members of CESA.
This article is the second in a series of short articles on how to deal with readymix concrete. The first article (How to use readymix concrete) appeared in the May 2016 edition of Civil Engineering (pp 82-83). We trust that these 'how-to' pieces will address any uncertainties about the correct handling of readymix concrete.