The City of Cape Town (CCT), through turnkey developer Calgro M3 Developments, appointed Bigen Africa to create a public transport facility with the emphasis on simplicity, sustainability and efficient operation for the underprivileged community of Wallacedene. It was the CCT's objective to provide social and economic up-liftment to the community through this R25 million facility. In addition, the new Scottsdene Housing Development Project increased the area's need for a reliable public transport facility. The facility is a place for people and should provide a service which would restore a sense of dignity in the community and with commuters, whilst stimulating social and economic development, following the principle that economic opportunities always follow places where transport nodes cross. The facility should furthermore be practical in its operation and design, allowing for safe and easy access, reducing the need (and cost) for intensive maintenance.
It must have broke your poor little heart, when the boys used to say, you looked better in the dark. But now they'd give all they learnt in school, to be somewhere in the dark with you. UB 40 (Homely Girl, 1989)
In recent months leading geo-technical solutions provider, Keller's Franki Africa, has enhanced its reputation with several history-making basements in the Sandton area. One of these, the basement for the new Old Mutual building on the corner of West Street and Rivonia Road (opposite the Gautrain station) turned out to be one of Franki Africa's most challenging projects in the area. While there were several reasons for this, the three main challenges were the extensive diabase dyke on the south-western side of the site, the presence of the Gautrain tunnel, which runs directly under the site, and the integration of the adjoining Sandown Mews development.
This year SAICE, for the first time, partnered with the South African Forum of Civil Engineering Contractors (SAFCEC) to host its annual awards event showcasing the most outstanding engineering achievements of 2014/2015. Also, for the first time in many years the event was held in Cape Town - at The Bay Hotel in Camps Bay on 16 October. The ever popular event again saw more than 30 projects entered into the various categories, and on the pages of this edition of the magazine we would like to share those with you.
In May 2012, the South African National Biodiversity Institute decided to build a tree canopy walkway to commemorate Kirstenbosch's centenary, making the 'canopy' experience and new views of Cape Town and Table Mountain available to the public, including people who are wheelchair bound. The walkway had to blend unobtrusively into the forest, minimising both the visual impact on the area and the physical impact on the forest. A delicate structure, carefully positioned between the trees, with colours blending in with its surroundings, was needed. A two-year process of creative collaboration between architect Mark Thomas and structural engineer Henry Fagan resulted in a steel and timber footbridge meandering through and over the treetops of the Enchanted Forest, a natural treasure of well-established trees.
Upgrading of the Umgeni Road Interchange was required to reduce traffic congestion on the busiest section of National Route 2 in Durban, KwaZulu-Natal. The South African National Roads Agency appointed Hatch Goba for the design and contract administration of this project, which was co-funded by the eThekwini Municipality. The construction contract was awarded to the Rumdel Cape / EXR / Mazcon Joint Venture. The site is surrounded by residential and commercial properties, the Umgeni River, the Inanda Road Interchange and services which include bulk water and wastewater pipelines, a Transnet gas pipeline, heavy and medium voltage electrical lines and telecommunication cables. These constraints, together with the need to minimise disruptions to the extremely high traffic volumes, presented major challenges for the design and construction of the interchange.
Mining activities on the Witwatersrand exposed the underground geology - rich in pyrites - to oxygen and water, causing oxidation with the pyrite-bearing rock, forming acid mine drainage (AMD). When underground dewatering activities ceased, water levels in the mine basin rose, threatening to pollute rivers and streams if urgent action was not taken to mitigate the risk to people and the environment. The Department of Water and Sanitation directed the Trans-Caledon Tunnel Authority (TCTA) to implement an emergency solution. TCTA commissioned AECOM and its sub-consultant, Golder Africa Associates, to design and implement a short-term intervention (STI) solution for the AMD problem.
Eskom is building the Medupi Power Station as a dry-cooled coal-fired power station near Lephalale. On completion it will deliver approximately 12% of South Africa's electricity and will be one of the biggest dry-cooled power stations in the world. The project consists of many design and construction packages. Nyeleti Consulting's scope was, amongst others, the design of 23 substations, 16 other process-type buildings and approximately 2.5 km of interconnecting trenches. This involved multidisciplinary engineering services, as well as coordinating a number of disciplines and design packages.
The 70 years old Langa Interceptor Sewer, which drains the Langa residential area, is one of only a handful of known egg-shaped sewers in the Cape Town metropolitan area. Since the mid-1980s severe siltation has been reported in the sewer, which has required regular intensive mechanical (bucketing) cleaning. When the 510 m long sewer, which traverses a traditional initiation site for approximately 300 m, started experiencing regular structural failures, the City of Cape Town (CCT) appointed AECOM SA (Pty) Ltd to construct a sand trap and rehabilitate the sewer. The first phase of the project was completed in 2009 with the construction of the sand trap in an upstream position outside the initiation site boundaries.
Th e KwaDukuza Municipality (KDM) in KwaZulu-Natal is one of the fastest growing municipalities in South Africa. In October 2009, the KDM launched its Electricity Priority Projects (EPP) programme in response to the growth in electricity demand.
A 14.23 km two-lane pavement of Section 11 of National Route 2 between Soutwerke and Colchester in the Eastern Cape started showing signs of distress and extensive cracking. After considering the structural condition of the existing road, the financial viability of road upgrades, the risk off-looding, and road capacity implications (keeping in mind the development of the Coega Industrial Development Zone), it was proposed that the two-lane road be upgraded to a four-lane divided highway
A heritage impact assessment for the proposed development of the former Produce Market in Newtown, Johannesburg, was approved by the South African Heritage Resources Agency (SAHRA) in 2009. A heritage management plan was adopted in 2011 which outlined the conceptual approach to adaptive reuse and restoration of heritage resources on the site, including the potato sheds and the steel bridge, and became the base set of guidelines for the duration of this project. In 2013 the potato sheds were incorporated into a new mixed-use development (comprising a shopping centre, office space and a parking basement) - Newtown Junction - which involved a rigorous restoration process and significant efforts to acknowledge its original trading function while maintaining its heritage reputation. At the same time, plans were made to restore the steel bridge and to open it to the public, linking the new retail development to the upper level of the Market Theatre. The project saw the design team adopt a hybrid approach consisting of partial restoration, partial replacement and partial additional strengthening.
As a result of the bucket eradication project in Dordrecht, the amount of sewage emanating from the town has increased in recent years, with more waterborne sewage being planned in the near future. This necessitated the upgrading of the current wastewater treatment works (WWTW) from its current 1 Ml/d capacity to a future 2.8 Ml/d capacity. This project consisted of the initial upgrades to the WWTW comprising a new inlet works, a new chlorination building with a chlorine contact tank, as well as a treated sewage effluent storage pond to cater for future irrigation purposes. The upgraded Dordrecht WWTW combines a conventional pond system with new technologies, including chlorine disinfection. The condition of the existing ponds was also improved with some necessary maintenance work, increasing the life expectancy of the current ponds. Dordrecht currently uses four sewage pump stations to pump sewage to the head of the WWTW. These pump stations frequently overflow due to pump failure and Eskom load-shedding. The construction of sewage overflow ponds was not permitted as part of this project, due to the local environmentally-sensitive areas (wetlands). Back-up generators were, however, permitted to prevent pump stations overflowing during load-shedding.
The Preekstoel Water Treatment Works (WTW), located in the Hemel and Aarde Valley near Hermanus in the Western Cape, was designed to treat mainly surface water from the De Bos Dam. Between 2010 and 2014 the WTW was refurbished and an additional treatment lane was constructed for the treatment of borehole water. This lane comprises the first full-scale biological iron and manganese removal plant in South Africa, with a total capacity of 10 Ml/d. The previous treatment processes at the WTW were inappropriate for groundwater treatment, since the groundwater is rich in iron and manganese. The project team proposed the adoption of a biological filtration process to treat borehole water, which has proven to successfully deliver treated water that is within the stipulated iron and manganese limits applicable to drinking water standards in South Africa.
Th e purpose of the project was to upgrade Section 1 of the N7 road network between the Melkbos Intersection (km 18.0) and the Atlantis Intersection (km 25.5) just north of Cape Town to freeway standards. This was done by increasing the existing design speed to 120 km/h, improving road safety levels and increasing carrying capacity to the required levels for accommodating current and future traffic volume increases.
This project, the new headquarters for the Department of Environmental Affairs (DEA) in Pretoria, includes the design and construction of the building, as well as the operation of the facility for 25 years. It involves the construction of a three storey office building including basement parking, ministerial suites, and conference facilities with landscaped cafeteria areas totalling 44 539 m2. It takes into account energy-reducing measures and state-of the-art building management systems to maintain a maximum overall energy consumption of 115 kWh/p/annum. The building was awarded a 6-Star Green Star Rating - the highest ever rating for any office building in South Africa.
On the UNESCO World Heritage Site, the Cradle of Humankind, Australopithecus sediba - a hominid fossil and arguably one of the most important fossil discoveries in the history of homo sapiens - was found.
IMPORTING FRENCH TECHNOLOGY For the periodic maintenance of National Route 3 Section 1 from Candella Road (km 8.5) to Paradise Valley (km 17.0), in the eThekwini Metropolitan area, it was decided to implement French technology. This would be the first full-scale EME (Enrobé à Module Élevé) construction project in South Africa. EME consists of a low penetration binder (10/20 pen. grade) that is extremely hard, but not brittle, resulting in a very stiff asphalt layer that has good fatigue and rutting resistance. These features make it an excellent alternative to concrete pavements. In addition, the inclusion of 20% RAP (reclaimed asphalt) pushed the boundaries even more, as standard practice in Europe is to only include virgin material.
Initially built between 1926 and 1940, the Mouille Point / Sea Point sea wall and promenade have developed into one of Cape Town's most popular public amenities. This section of wall, built between the low- and high-water marks, consisted of a 3.4 m high mass concrete wall founded on massive concrete footings at approximately 1.8 m. The wall was faced with granite blocks and capped by a heavy reinforced concrete cope with concrete bollards and open rails. Pounded by frequent storms, breaches began appearing in the sea wall where granite facing had collapsed and water penetration through the wall began causing significant erosion of fill under the paving. Emergency repairs undertaken to seal the breaches left the wall with an unattractive 'patchy' look and were themselves subject to frequent failures. In 2011 the City of Cape Town undertook a long-term study of the sea wall and promenade and in 2012 a contract was let to undertake the full structural rehabilitation of the sea wall, including major upgrading of the promenade and adjacent amenities. The part covered in this project is the section of sea wall from Three Anchor Bay to the Green Point lighthouse, a length of approximately 650 metres forming Phase 1 of the rehabilitation.