Dulce Simoes Lateral Support, Piling

Article Published in April 2018 edition of Construction World

Once complete, Pinnacle Towers in Nairobi, Kenya, with a height of almost 300m, will be the tallest building in Africa. For Keller company, Franki Africa, which is in the process of doing the geotechnical work, this prestigious project has been somewhat of a milestone.

“Firstly, it has been a technically challenging undertaking and we are pleased to have provided a successful and cost-effective solution and, secondly, it marks our entry into this region of East Africa – thus fulfilling one of the important goals in our medium-term growth strategy,” says Franki contracts manager Roberto Alves.

The building, in Nairobi’s Upperhill area, will cost an estimated USD 194 million. It consists of two towers, the tallest of which will have 70 mixed-use floors and the other will be a 45-floor Hilton Hotel developed by Hass Petroleum and White Lotus Group. There will also be 200 residential houses run by the Hilton Hotel that will include one-bedroom, two-bedroom, and three-bedroom fully furnished luxury apartments.

“Pinnacle Towers will have a helipad at over 243m, making it the highest on the continent. We thought it wise to put the helipad here so that people can fly directly to the hotel and beat Nairobi’s hectic traffic,” Hass Petroleum Executive Chair, East and Central Africa Abdinasir A. Hassan said during the laying of the foundation.

Franki solves lateral support challenge

“During the excavation phase it became apparent that lateral support was required, and we were appointed to provide that support with a 3,000m² nailed wall”, says Alves.  “As most of the excavation was already completed before we began the support work, additional earthworks were required to create access platforms in the excavation pit.”

He added that the client was so satisfied with Franki’s performance during the lateral support works, they recommended to the main contractor that Franki should be appointed as the preferred specialised subcontractor for the piling works, which was duly done.

Piling in very hard rock

Immediately after completing the lateral support works in December 2017, the Franki team began with the piling works. “The biggest challenge we face in the fulfilment of this phase of the project is drilling through up to 6m of very hard rock with a strength of more than 100MPa to install almost 400 no. auger piles using three different diameters: 800mm, 1 000mm and 1 200mm,” says Alves adding that additional challenges include the excavation pit with a depth of 25m, as well as a tight 120-day completion programme.

To accomplish the task two piling rigs, a 66-ton crawler crane and three cluster hammers were imported into Kenya at very short notice, which was a task in itself.

Pinnacle Towers, which are expected to be completed by December 2019 will be among the tallest buildings in the world, with Dubai’s Burj Khalifa being the tallest currently at 800m.

Franki Africa MD, Errol Braithwaite says that the company is proud and pleased to be able to support such a prestigious project in Kenya “We look forward to growing our business and broadening our service offering in this beautiful country”, he says.

Braithwaite added that the main reason that Franki is able to deliver service at the highest level in Africa is because of the combination of global strength through being a Keller company, combined with Franki’s local focus in Africa over so many years.

“Being a global player but deeply rooted in local businesses makes Keller the number one choice for customers searching for reliability, excellence and efficiency anywhere in the world.  Our global strength and expertise mean that we are able to bring the best possible geotechnical solutions, products and equipment to every project; while our local focus means that we enjoy in-depth knowledge of local markets and ground conditions,” he says.

“No project is too big, or too small, or too complex for us. And in terms of Africa we are geared up like no other geotechnical company in the world.  We have permanent offices and yards in South Africa, Mauritius, Mozambique, Tanzania, Zambia, Kenya, Ghana and Angola. We are also registered in Uganda, Botswana, Swaziland, Lesotho, Seychelles and Namibia. Our French speaking colleagues are present in Morocco, Cote d’Ivoire and Algeria and our middle eastern colleagues are present in Egypt.

“Add to this the depth of global experience that the Keller group has and our experience of moving equipment across the continent, Franki’s service in Africa is second to none,” he concludes.



Artist’s impression