Partial collapse of Ezimbokodweni River Bridge sparks urgent call for infrastructure maintenance
THE Ezimbokodweni River Bridge partial collapse highlights the need for comprehensive infrastructure maintenance across the nation, said Chris Campbell, the CEO of Consulting Engineers South Africa (CESA).
"The partial collapse of the bridge is a reminder that while we focus on new projects, we must not neglect our existing infrastructure, much of which is deteriorating and in dire need of attention," said Campbell in a statement.
A team was assigned to assess the damage on the N2 bridge following Tuesday's partial collapse.
Campbell said there was limited research on the overall state of bridges nationwide, and this made it difficult to prioritise interventions effectively.
"But this does not mean it must not be done... This incident has highlighted the urgent need for routine maintenance across all infrastructure assets, not just bridges but for roads, buildings, and water and sewerage systems, to ensure their longevity and safety. Proactive maintenance will provide us with a clearer picture of the health of the country’s infrastructure and allow us to protect our citizens better."
According the South African National Roads Agency SOC Limited (Sanral) preliminary findings, the damage to the Ezimbokodweni River Bridge resulted from the failure of span four of the bridge.
This was as a result of the malfunctioning of its bearings, particularly the concrete rocker bearing on the east side and the central bearings.
These bearings, which support the bridge deck, are susceptible to excessive vibrations such as seismic or earthquake loads, which can induce cracking and splitting.
Built over 64 years ago in the early 1960s, the Ezimbokodweni Bridge consists of six spans, with a total length of 137.16 meters. It carries the N2 southbound carriageway over the Ezimbokodweni River from Durban to Port Shepstone.
“Over the bridge’s 64-year lifespan, the vibrations, along with potential age-related deterioration, likely caused spalling and cracking of the concrete. The deterioration would have exacerbated the corrosion of the reinforcement within the bearings, weakening them and ultimately leading to their failure," said Sanral.
The road agency said a full inspection of the remaining bearings was being undertaken as all bearings on the bridge may need to be replaced due to its age and vulnerability.
"Challenges to the repair work include high-water levels and the ongoing wet season, which will impact access to the site. To manage this, Sanral will do the work in two phases.
“Phase one will involve temporary support for span four, lifting the bridge deck, installing temporary supports with rubber padding, and lowering the new temporary deck to the required road level to allow it to reopen by December 13, before the holiday season.
“Phase two, expected to begin in January 2025, will entail the replacement of all bearings to prevent future failures and to ensure the continued functionality of the bridge. This phase will also address critical repairs, including the restrained cracking.”
At a media briefing on Thursday, Mkhuleko Hlengwa, the Deputy Transport Minister, said: “We are calling for public patience as we respond to this crisis on the N2 south bound. Sanral is doing preliminary work to assess the extent of the damage and a briefing will be given to the minister in due course.
“From the briefing I received from Sanral, there will be two sets of interventions that will be urgently undertaken to lift the bridge up. The assurance we want to give is that there is no structural damage to the bridge. These are ‘wear and tear’ elements, which have broken down and will require replacement. Sanral's technical team is currently assessing how quickly this can be done.”
He said it was Sanral's intention to ensure that traffic flow resumed on this road within a period of three to four weeks, in time for December.
"In January, Sanral will undertake comprehensive repairs of the damage to the bridge. This carriageway is due for an upgrade by Sanral during which further improvements will be made on this road.”
Work will be planned to align with Sanral’s long-term bridge upgrade plans and will be executed with temporary short-term traffic closures, either at night or on weekends.
Dudley Mbambo, Sanral’s Acting Regional Manager for the Eastern Region, said regular inspections of all its structures were undertaken, including bridges, as part of its bridge management system.
"The most recent assessments were completed in February this year for the entire country.”
He added that the Ezimbokodweni River Bridge received 98% in its last assessment in February and that the bridge failure was due to wear and tear.
He said the technology for bridge construction had advanced since the '60s when concrete bearings with corroding steel bars were used, and that the steel bearings being currently used do not corrode.
In the interim, motorists, who have had to use alternate routes, said they were frustrated.
Thiru Chetty, who lives in Amanzimtoti and owns a trucking business, said: “Business operations are experiencing major delays in deliveries into the Southgate Business Park and anything further down the N2. On average, the travel time is now taking us two hours or more as compared to the usual 20 minutes between Prospection and Southgate.”
He added that the detour routes were not conducive to heavy motor vehicles and it impacted their fuel consumption.