We were appointed by SANRAL to provide engineering and design services for a 36 km section of the R61 between Queenstown and Mthatha, as well as construction supervision services for the first 18 km portion from Coughlan to Baziya.
The existing road was upgraded to provide a carriageway with two 3,7 m lanes and 2,5 m surfaced shoulders, while the aged pavement was completely replaced with conventional layers and a Cape Seal surface.
Meanwhile, the ground line of this section of the road corridor was significantly improved, involving major cut-to-fill operations with one of the excavations up to 10 m deep.
The project also entailed major structural work, including an impressive three-span crossing over the Mbashe River. Standing 18 m above the river, one of the bridge’s two piers was founded on piling that was sunken 8 m down to the river bedrock.
In addition to the three bridges, other structures include three 3 m x 3 m agricultural underpasses, as well as a single 2,4 m x 2,4 m, a double-, a triple- and a quadruple-barrel cast in-situ concrete culvert.
One of the complexities of this project was mitigating the impact of construction activities on the daily heavy traffic.
Safety was a major priority right from outset when a series of temporary bypasses were constructed to divert two-way traffic to the one side of the road to allow work to commence on the other side.