The Gauteng Department of Roads and Transport says remedial work has started on the damaged R55 (Quagga Road) in Laudium, Tshwane.

This comes after a sinkhole formed on the busy route earlier this year forcing the department to close the road.

“The Department investigated remedial repair methodologies to expedite repairs to the road and following a detailed dolomitic stability survey conducted by geotechnical experts, the estimated cost for the repairs is R12.1 million,” explains Department spokesperson Melitah Madiba.

The results of the seismic survey and drilling programme together with proposals for rectification were submitted to the Council for GeoSciences (CGS) for approval. CGS is mandated to develop and publish world-class geoscience knowledge products and render geoscience-related services.

“A Departmental team of experts has been monitoring the area around the sinkhole for the past ten weeks, and no further settlement or movement was recorded during this time,” Madiba notes.

Repair works

The team has started the process by pouring concrete into the throat of the sinkhole. This exercise is meant to throttle the sinkhole so that no further collapse can occur, particularly during rainy seasons.

“With the throat throttled, the process will commence to stabilise the area through dynamic compaction to collapse whatever unstable ground there is within the immediate surrounds. Suitable fill material will then be imported and compacted until the area is totally stabilised and returned to ground level.

“Upon completion, holes will be drilled so cement grout may be pumped under pressure into the rock formation to fill whatever voids may remain. Construction to the affected section of the road will then start to return it to its previous state. Total construction is expected to last approximately four months,” Madiba explains.

Motorists have been urged to utilise alternative routes during when continued on the route.