When a large (45 megalitre) concrete reservoir has degraded to such an extent that it is no longer serviceable as a water retaining structure, all is not lost, as Aquatan (Pty) Ltd proved when the company recently rehabilitated the Waterval Reservoir in Roodepoort.
There is a true saying, "No man is an island". The more we think we can go it alone, the more we discover that we need others to assist, facilitate and support. Organisations like SAICE and other built environment societies exist because individuals came together to address issues that they could not deal with on their own. It is an historic fact that many organisations then went on to become highly successful in addressing the needs, aspirations and expectations of their members.
I looked around the room. Nearly every head was nodding in agreement. The audience was a meeting of the Council of the South African Institution of Civil Engineering to whom I was delivering a presentation titled, "South Africa - Engineering to Thrive".
The decision to use fly ash in the raft foundation of the world's tallest building, the Burj Khalifa Tower in Dubai, was based on technical criteria. The aggressive weather conditions in the Dubai region, with Persian Gulf temperatures of up to 50°C, required the concrete to be able to resist the thousands of tons bearing down on it, be as impermeable as possible, and resist chloride and sulphate attack. The presence of fly ash in the concrete mix would also limit peak temperatures of mass concrete pours, thus reducing the potential for cracking.
The environmental advantages of the extraction, destruction and possible utilisation of landfill gas (LFG) have been well documented, and South Africa is in an advantageous position in terms of the Clean Development Mechanism (CDM) provisions of the Kyoto Protocol, an initiative of the United Nations Framework Convention on Climate Change (UNFCCC). In addition to the environmental benefits associated with a significant reduction of landfill emissions, the sale of such quantifiable units, called "Emissions Reductions" (ERs), can provide a sustainable source of funding that can be channelled back into waste management initiatives. The potential use of the gas as a renewable energy source for power generation, coupled with the revenue derived from the sale of the electricity is an added bonus.
In the absence of advanced spoil removal systems in the past, it was standard practice for ballast cleaning machines to spoil the fines screened from the ballast bed alongside the track. This had numerous disadvantages.
Western Cape municipalities and government departments, as well as property developers and others in the private sector, will soon be able to measure how effectively they are dealing with the impact of climate change.
The City of Tshwane embarked upon a project to record and classify all storm water and environmental assets. The objective is to manage these assets in a sustainable way, while protecting the city's natural resource base and simultaneously building a green economy. SRK Consulting was appointed to assist on the project.
A clear understanding of the factors that need to be taken into consideration when planning and designing bicycle facilities is needed in order to make it a sustainable means of transport. Government also has a role to play through policy documents in ensuring that bicycles can be regarded as a sustainable mode of transport.
This article follows on the overview article published in the May 2010 edition of Civil Engineering (pp 20 - 26) and covers a portion of the work done after completion of the Phase 1 Main Maritime Contract.
An ultra-thin continuously reinforced concrete pavement (UTCRCP) on the N1 freeway near the Huguenot Tunnel in the Western Cape has made engineering history. Designed by a joint venture between UWP Consulting and PDNA Consulting Engineers, the UTCRCP was placed on a 4,3 km long section of truck crawler lane. This was the first large-scale application of UTCRCP technology in the world.
If there ever was a book that this reviewer was biased in favour of, it's this one. Not least because the long list of contributors includes many of his current and former associates at the City of Cape Town, Divisional Council of the Cape, Ninham Shand Consulting Engineers, and the water, environmental and historical activist community of Cape Town. Prominent among these contributors is Tony Murray, whose unpublished research tour de force, "Much water under many bridges : the history of the catchments, rivers, and drainage systems of Greater Cape Town", underpins a sizeable chunk of this lengthy (400 page) book.
Golder Associates' construction division has been successful as lead Engineering, Procurement and Construction Management (EPCM) contractor for Optimum Coal Mine's newly-built water reclamation plant that will treat up to 15 Mℓ/day of excess mine water into potable standards for both drinking and release back into the environment.
Over the last 30 years geosynthetics have become one of the most widely used products in the engineering field due to their versatility in application, behaviour, handling and cost. All designs using concrete, asphalt and steel can now be improved by including geosynthetics.
A unique commitment to minimising the impact on the environment underpinned all work completed during the recent upgrade of the N2 between Tsitsikamma and Witelsbos. The 14 km section of this strategic and scenic National Road through South Africa's Garden Route was the final section to be upgraded to toll road standards. The scope of work included the widening of the road to accommodate emergency lanes, and flattening of the horizontal planes to increase visibility. This involved realignment of the road, removal of undulations to create a better geometric shape and upgrading the subsurface - all of which has resulted in a significantly improved driving surface.