The first sinkholes opened up during pouring rain earlier this month, after which further rain a week later caused another enormous sinkhole to open up next to the road between Daniëlskuil and Kuruman.
The Department of Roads and Public Works had to officially close the road.
John Dickie of the Speleological Association of South Africa and Dirk van Rooyen of the Wits Exploration Department were also exploring the passages and chambers beneath the road on Wednesday (25/01).
According to Dickie, the passage underneath the road is approximately 4 m high and 3 m wide. From there, the crack becomes flatter. It becomes 1 m high and 10 m wide and stops 30 m on the other side of the road.
Meanwhile, the department has appointed a geological company. Chrystal Robertson, departmental spokesperson, says a survey about the nature and extent of the holes is being compiled and the stability of the road is also under investigation.
The geologist will make recommendations about how the road is to be repaired.
The department wants to repair the road as quickly as possible.
“It is very inconvient for people and influences the local economy. Our greatest concern is to keep the water away from the road.”
Richard Roberts, a consulting engineer from SMEC South Africa who coordinates the drilling, says the chamber beneath the road is a cause for concern.
“The underground holes and sinkholes will probably need to be filled up.”
Roberts says the company drill holes of about 40 m deep to map invisible sinkholes. They have drilled into several chambers on both sides of the road and around the sinkholes.
Gert Saaiman of GS Survey does a topographical survey in the empty space that the sinkhole has fallen into. He uses GPS devices to measure the high and low points.
He will compose a map of the area that will indicate the road, the sinkhole and the empty space.
He believes the empty space has sunk in over a period of years. It is now presumably lower than the floodwater ditches that run beneath the road. The water can therefore not properly flow underneath the road.
One option can be to build a temporary wall to keep water away from the empty space and the road.
However, much more information needs to be provided by a variety of experts.