Construction World September 2018

The foundations are for two bridges that will be built over the Swakop River, which is the largest temporary water-bearing river – with a 30 100 km 2 catchment area – in the dry western part of Namibia. The bridges will be situated on the outskirts of Swakopmund just before the Swakop River reaches the Atlantic Ocean. They form part of the upgrade of the old salt road to a new highway between Swakopmund and Walvis Bay. Stefanutti Stocks Geotechnical mobilised its Bauer BG28 piling rig (with a BV1500 HD oscillator) and Kobelco Crawler Crane from South Africa for the project. The geology in the Namibian desert consists of sand, calcite, granite and boulders. All the deep pile foundations will have their 900 mm diameter sockets founded up to four metres deep into the calcite and granite. However, in some cases to get to this rock, it was required to drill over thirty meters into the sand and through boulders which tend to move when drilled, making drilling very difficult. Permanently cased oscillator piling was deemed most suitable in these challenging geological conditions. Piling for bridges in Swakopmund Stefanutti Stocks Geotechnical is applying its wealth of experience in deep pile foundation construction in Namibia, where it has installed seventy-six 900 mm diameter permanently cased, raked oscillator piles.

BELOW: Deep pile foundations for river bridge in Bushbuckridge in Mpumalanga.

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CONSTRUCTION WORLD SEPTEMBER 2018