A 14.23 km two-lane pavement of Section 11 of the National Route 2, between Soutwerke and Colchester in the Western Cape, started showing signs of distress and displayed extensive cracking, which started to pose a health and safety risk for drivers.
In 2005, the South African National Roads Agency Limited (SANRAL) undertook to rehabilitate the route, which runs in a north-easterly direction to where it terminates at the intersection to Colchester. SANRAL appointed a joint venture between Aurecon and Semenya Furumele Transportation Engineers (the Semenya Aurecon Joint Venture) to carry out the professional services for this project.
After considering the structural condition of the existing road, the economic and financial viability of road upgrades as well as road capacity implications, it was proposed that the existing two lane road be upgraded to a four-lane divided highway. This meant that a new bridge had to be constructed alongside the existing bridge over the Sundays River.
Following a detailed hydrological and hydraulic analysis, it was found that the existing bridge was too low to accommodate the design flood with the required freeboard. The existing bridge deck had therefore to be raised by approximately 2.3 m.
The construction of the new bridge over a perennial river with challenging foundation conditions as well as raising the deck of the existing bridge required innovative design solutions and construction techniques which makes this project a testament to the excellence in the use of concrete.The construction of a new bridge, together with the raising of the existing Sundays River Bridge on the route, was successfully commissioned in June 2014.
Approximately 55 000 hours were worked by 354 workers without a serious incident. At the height of construction activities, the main contractor had 134 workers on site with 85 sourced from the local community. The project was also used for training SANRAL personnel with one engineer and eight students spending time on site. The contractor tendered a target for expenditure on Small, Medium and Micro Enterprises (SMME’s) of 12% of the total fee. The achieved expenditure was in excess of R75 million or 23.2%.
The new bridge over the Sunday’s River provides the client with a durable structure in a very aggressive environment that will require minimal maintenance during its lifespan. Road conditions and safety have significantly improved and the road is able to accommodate the growing traffic volumes generated by the Coega IDZ.
The project achieved the Best Photo award, as well as a Commendation in the ‘Technical Excellence’ category, at the South African Institute of Civil Engineering (SAICE) Eastern Cape Branch Awards in 2015. At the annual SAICE event, the project received a commendation in the category of Engineering Excellence with a value of R50 million – R250 million.