Stefanutti Stocks Geotechnical successfully completed the design, supply and installation of piling to a precast beam bridge that was constructed over the Xixamba River. The bridge, located in the Bushbuckridge area of the Ehlanzeni District of Mpumalanga, forms part of a new road from Marijane to Merry Pebbles that runs through an area marked by many small agricultural settlements. The new road replaces a narrow dirt road and will improve the infrastructure in these rural areas and facilitate better access to schools and clinics as well as access to employment and business opportunities for the local communities.
After undertaking the geotechnical investigation work Stefanutti Stocks Geotechnical submitted a design and supply proposal based on the information on the soil conditions identified during investigation. This proposal included the installation of twenty-one temporary cased, cast in-situ piles, to depths of up to 25-metres. The most cost-effective solution was to use piles ranging between 900mm and 750mm in diameter.
The area is characterised by different classes of rock, ranging from soft rock (R2) up to very hard rock (R5). The contract required drilling through 220 metres of these different classes of rock, for which Stefanutti Stocks Geotechnical utilised its Casagrande B200 piling rig.
Heavy rains resulted in very wet soil conditions, that complicated the piling operation, in particular the casting of 158m3 of concrete, supplied by a ready mix plant located just outside of Hazyview. The very hot and humid conditions at Merry Pebbles, as well as the two-hour travelling time from Hazyview, resulted in the use of admixtures to ensure the workability of the concrete.
The site team rose to all the challenges, and successfully completed the project well ahead of time and to the satisfaction of the client.
“One of our objectives on our geotechnical contracts includes establishing and building good relationships with our clients and the consulting engineers, and we would be delighted to work with, or for, the Merry Pebbles team again,” says Shaun Butler, managing director of Stefanutti Stocks Geotechnical.
- An aerial view of the wet conditions on site on the banks of the Xixamba River.
- Casagrande B200 piling rig drilling with temporary casing to seal of the ingress of water.