Rehabilitation work on Kilburn street bridge, in Discovery, Roodepoort, is scheduled to start in the first quarter, following the total collapse of the bridge in early December owing to heavy flooding experienced across Johannesburg.
The Johannesburg Roads Agency (JRA) has prioritised repairs to the Kilburn street bridge at an estimated cost of R15-million owing to previously identified severe embankment erosion, the collapse of the ageing corrugated stormwater culvert pipe and the road layers.
Severe flooding in December led to the total structural collapse of the culvert and road section. The road section has been closed and a traffic diversion plan is in place, the JRA said on January 10.
“An initial design has been completed, which includes a new precast box culvert large enough to carry higher capacity loading and maximum water levels. The old galvanised metal steel corrugated pipe was severely eroded and became too small to support the 14 m wide dual carriageway with a central barrier and single sidewalk, as well as the water flow capacity,” JRA acting CEO Louis Nel said.
The JRA will appoint a contractor through emergency regulations.
In addition, as the bridge culvert falls within an environmentally sensitive area, the JRA has also made an emergency application and applied for an extension from the Department of Agriculture, Rural Development and the Environment, because these applications can ordinarily take up to 24 months to approve.
“We envisage a review of the initial design once reconstruction commences and geotechnical studies have been undertaken to verify the soil conditions. This may impact the initial projected R15-million reconstruction cost,” Nel warned.