A Stefanutti Stocks Oro Projects joint venture (with ORO Projects being a 32% partner) made a bid for the construction of a water treatment works reservoir for uMhlathuze Water in Richards Bay in late
- The project was awarded to the JV in March 2015 and work on site commenced in mid-April 2015.
A second reservoir, also undertaken in joint venture (ORO Projects 16%, Vitatype 99 CC 16% and Stefanutti Stocks Civils KZN 68%), was awarded in mid-2015. Clearing of this second adjoining site began in September 2015, at which time the civil construction of the first reservoir was at 42% complete.
Each contract entailed the construction of a 20-megalitre reservoir with associated bulk infrastructure, bulk earthworks and pipework.
The construction methodology on both reservoirs proceeded as below:
- bulk earthworks – excavation;
- layer works – selected granular material reinforced with geogrid flexi mesh;
- construction of the no fines layers followed by a 10.00mm thick mortar topping;
- construction of the 50m diameter reservoir wall footing floor slab;
- construction of the 12m high reservoir walls;
- construction of reservoir domed concrete roof slabs cast monolithically with ring beam;
- pre-stressed post tensioning of the walls, ring beam and domed roof simultaneously;
- water test;
- pipework; and
- backfill and landscaping.
In both contracts the reservoir bases, walls and floors are completely separate structures separated only by Kilcher Bearings that have a load-bearing capacity of 18 ton/metre.
The pipework tie-ins involved tying in to existing live lines with specified limited, restricted intervals, so as not to interrupt the water supply to the nearby Mondi mill.