Pretoria - Experts have started percussion drilling to investigate the size of the sinkhole along the N1 south in Centurion, near the so-called Flying Saucer Interchange.
They will then recommend appropriate remedial action to the SA National Roads Agency (Sanral).
The entity’s regional manager, Progress Hlahla, said the current challenge was determining the diameter and depth of the sinkhole underground.
After closing one lane and erecting barricades to allow traffic flow while keeping vehicles safe from the cracks, experts have undertaken to understand what they were dealing with, largely because different sinkholes require different remedial actions.
Hlahla said dealing with sinkholes was complex because there was no one-fits-all solution.
He said the size in diameter and depth, and other factors such as the type of soil and the environment, determined the type of remedial action required to close every sinkhole properly.
“I can definitely say yes, indeed, there is some work being carried out right now at the sinkhole. We have drills there assisting with geo-technical investigations.
“We had to first start off draining the sinkhole by diverting the water, because water would make it worse.
“We are now at the investigation and design phase,” said Hlahla.
He said he could not yet say how soon motorists could see the blocked-off lane reopened because sinkholes required extreme caution and careful study to be closed properly. However, he was sure the work would be done quicker than normal to allow a smooth flow of traffic.
Centurion is prone to sinkholes because of the dolomite underground, and this has cost the City of Tshwane and provincial government millions in repairs.
Hlahla said motorists travelling southwards towards Johannesburg should consider using alternative routes.
“From Polokwane, take the off-ramp at Proefplaas Interchange (145) towards Pretoria CBD using the N4/M2 and join the M3 towards Fountains and join the N14,” he said.
“From OR Tambo International Airport, continue on the R21 towards Fountains circle and join the N14.”
Pretoria News