Remedial works have commenced on the damaged R55 (Quagga Road) in Laudium, Tshwane, the Gauteng Department of Roads and Transport said on Wednesday, 22 August.
This was after a sinkhole formed on the busy route earlier this year. The development saw sections of the road, between Second and Third Avenue, being closed to traffic, the provincial department said.
“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 R12.1m,” said Department spokesperson Melitah Madiba in a statement.
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,” said Madiba.
The team has commenced to pour concrete into the throat of the sinkhole, an exercise 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 explained.
Motorists have been urged to utilise alternative routes during when continued on the route.