After being awarded a commendation at the South African Institution of Civil Engineering Durban Branch Awards earlier this year, the Durban Harbour Tunnel Project was awarded the coveted SAICE national award in the category Technical Excellence. The R210 million project was designed by local consulting engineering firm Goba with the assistance of international consultants Mott MacDonald of London. Construction was carried out by a joint venture between South African firm Concor and Hochtief AG of Germany.
The management team of the Department of Cleansing and Solid Waste of eThekwini Municipality have turned conventional thinking on running landfills on its head with the revolutionary 'closed-loop' design and operation introduced at the Mariannhill landfill. The approach is to ensure that once waste comes onto site, nothing leaves. This entails constructing a good lining system, treating the liquid (leachate) produced, capturing and utilising the gas produced, and managing the odours that are always present with seven-day-old waste. The project was entered by the Durban Branch and earned a commendation in the category Technical Excellence.
Bridge No 422 over the Orange River near Zastron in the Free State was constructed in 1934. It is a magnificent feat of engineering and concerted efforts should be made to preserve it for posterity. The bridge, which was seriously damaged by vehicular impact, was recently repaired. Innovative answers were found for the challenging demands of structural stability, safety and economy.
The Gracelands pedestrian bridge across the Mooi River in the Muden area of KwaZulu-Natal has restored all-year community access across the Mooi River. The old bridge was destroyed by floodwaters several years ago. The new hybrid suspension bridge was designed and constructed using lightweight galvanised steel sections and was erected almost entirely by hand without heavy lifting equipment. A unique feature of the design for this hybrid suspension and truss structure was the inclusion of a lightweight bracing truss in order to reduce undesirable sway movements of the 90 m main span.
This project forms part of the prestigious development of the Knightsbridge complex at Century City. The structure provides pedestrian and golf cart access and carries services to Knightsbridge Island. Several challenges had to be innovatively overcome during design and construction. Not least of these involved the structural steel arches, which were to be constructed from a bent 457 mm tubular section. The final solution saw the tubular sections rolled and bent in Gauteng, transported to the DLE yard in sections where they were sandblasted, galvanised and welded. After this they were transported to site where they were erected adjacent to the bridge location before being moved into the final position. The structure incorporated existing piers, which had not been designed to withstand significant lateral load. This required the arch to be 'tied' so as not to induce lateral loads onto the pierheads.
The intent of the developers of the Pinnacle Point Beach and Golf Resort was to transform a prime cliff top site on the southern Cape coast into a world-class residential resort and golf venue. The site features two secluded beaches, indigenous Cape vegetation and one of the most temperate climates in the world. However, developing the area necessitated overcoming the challenges posed by a geologically difficult and environmentally neglected site.
The new Umhlanga stormwater outfall pier is a continuation of a box culvert which is also under construction at present. The pier will extend approximately 85 m across the beach to a deep-water channel to ensure maximum dispersal of stormwater into the sea. It will be unlike any constructed in the region previously with long-span sections on columns to permit continuous access along the beach. The architectural styling has been a very important element of the design and is in keeping with the proposed improvements to the promenade.
A bridge constructed across the White Mfolozi River at Qwasha, in the district of Ulundi, provides long-awaited relief for many of the scholars at Nomzimani High School, who for years have had to cross this dangerous river to get to school. The decision to provide for vehicles to cross the river as well will add considerable benefit to the Nobamba community to the southwest of the river, as their travelling distance to Ulundi will be reduced by over 20 km. The construction of the bridge and associated roadworks made use of labour-intensive techniques to provide some 3 500 person-days of local work opportunities.
The Makwane Road Project in QwaQwa in the Free State was completed in December 2006 after a 24-month construction period. The project was carried out under the Expanded Public Works Programme (EPWP) and consisted of 19 small projects involving 27 small, inexperienced local contractors. The existing, very poor quality dirt road (13 km) was upgraded to a high standard block road, with numerous benefits to the community and road users. The project was completed within time and budget. The project has been voted the best EPWP project in South Africa at the 2007 EPWP Recognition Awards.
The Tsitsa River Bridge project for the Laleni community in the Eastern Cape was recently completed. The project consisted of a bridge over 100 m long and 2 km of approach roads. Funding was provided by the South African National Roads Agency after the community petitioned the Office of the President. Numerous lives had been lost when community members attempted to cross the river on their way to the nearest town of Qumbu as well as local schools and clinics. The project provided a major economic stimulus to the region through the use of local suppliers and labour.
The Chris Hani District Municipality was faced with a lack of sanitation delivery. In 2004, they appointed Arcus Gibb as the consultants and project managers / implementing agents for the Engcobo sanitation project. The scope of works comprised the construction of 5 512 Archloo toilets in Wards 1 and 3 in Engcobo. The project was funded through a Municipal Infrastructure Grant (MIG) and the Department of Water Affairs and Forestry (DWAF) at a value of R19,6 million.
The Eastern Cape Region of the South African Road Federation (SARF) a few years ago embarked on a project to provide a traffic training facility for junior learners in Port Elizabeth. This facility is situated adjacent to the NU9 Motherwell Library and comprises a surfaced road layout which includes a four-way intersection controlled by real working miniature traffic lights, traffic circle, road signs and markings, playground equipment for the grassed areas and a storage facility for the push scooters and mobile signs.
Designed for substantial floods and varying releases, the 26 m high Maguga regulating mass concrete weir consists of a 104 m long spillway, an outlet works comprising two 35 m long outlet channels with Crump weirs to facilitate accurate flow measurement. Innovative features include the use of river boulders to compensate for the constraints in crushed concrete aggregate supply. Outstanding engineering was also achieved by using the provided infrastructure for the provision of the power station, concrete bases for the hydropower machines, industrial floors and supports for the 61 t gantry crane. A pre-cast 20 m high stairway and offices were added to the original structure.
In a bold move aimed at entrenching a culture of global health, safety and environmental (HSE) standards in southern Africa's bituminous products industry, Sabita used the international stage of September's Conference on Asphalt Pavements for Southern Africa (CAPSA'07) in Gaborone to launch its Health, Safety and Environment Charter.
Infraset's innovative and pioneering approach to concrete technology gained it two awards in this year's Fulton Awards competition. Hosted by the Concrete Society of Southern Africa, this prestigious event showcases the very best examples of construction technology and design in southern Africa biennially.