Posted on July 14, 2016
By Chamwe Kaira, namibian
THE construction of a new container terminal at the port of Walvis Bay will be delayed due to what the Namibian Ports Authority has termed “geotechnical conditions.”
The new container terminal project consists of several contracts, of which the biggest contract is being undertaken by China Harbour Engineering Company Ltd (Chec).
The Chec contract includes 90% of all the works required for the project, and is valued at about N$3,44 billion. The project value is about N$4 billion. The current progress on the project as a whole is at about 56%.
Chec has furthermore progressed quite well with the local content requirements of the contract.
“As is the case with all large projects, this project is not without risks or challenges. Before the project commenced, Namport had already identified several risks to the project which required careful mitigation measures,” Namport said on Friday.
It said one of the biggest risks identified early on was the unique geotechnical conditions below the seabed at the project site, and how these conditions might affect the long-term settlements on the pavement as well as its effect on the deep foundations.
“Whilst the project site was specifically chosen for its relatively good geotechnical conditions compared to other areas in the bay, the prevailing geotechnical conditions at the site still required careful risk mitigation,” Namport said.
The firm said the difficult geotechnical conditions arise primarily due to a 25 metres thick diatomaceous silt layer which starts at approximately 20 metres below the seabed.
“This diatomaceous silt layer is a layer of dead organic matter, and its behaviour is generally not well-understood. The type of diatomaceous silt found at Walvis Bay is particularly uncommon worldwide, and research into the engineering properties of this type of silt is limited,” Namport said.
As a result, Chec spent nearly six months doing additional geotechnical investigations and research on this diatomaceous silt layer.
Further difficulties arose whilst installing deep piled foundations which support the new quay wall.
“These pile installation difficulties required remedial work and changes to standard installation methods. As a result of these difficulties, the project has seen certain delays, although Chec and Namport are working to minimise the effect of the delay on the overall project completion date,” it stated.
Namport had planned to commission the new container terminal in the first half of 2018, but it now appears likely that commissioning will only be in the second half of 2018.
“Again, Namport and Chec are working to minimise to the extent possible the schedule impact of these delays, and remain confident that the project will be completed successfully within 2018,” Namport said.
Source: namibian
