Construction World December 2018

Specialist Contractors or Suppliers

NKOMATI PHASE 2, MPUMALANGA

W ith the supply of readymix concrete from Belfast being erratic and taking up to two and a half hours to site, additional batching equipment had to be established to advance the programme. The anchors for the lateral support were designed based on the information and soil reports provided at tender stage. During construction it was found that 12 anchors on the first row and three anchors on the second row (within a localised section of the wall) were unable to achieve the required design capacity. In order to avoid any delays to the contract programme, two remedial actions were followed: • Anchors achieving very low capacities were abandoned and replaced with additional anchors. • Anchors not achieving sufficient capacity were reduced in capacity and additional anchors installed to make up the brought the rain, and access to the newly cut terrace was impassable. Roads were widened, gradients decreased, regraded with a binder, all eating up valuable time on the programme. Although almost a repeat design of the previously installed wall at Nkomati, budgets based on previous rates were trimmed to the extent that there was no float in time or cost. Ore extraction was declining along with its quality, and everything now fell on the critical path. The contract award

required capacity. The reasons for the anchors not achieving the required capacity was the basis of a supplementary geotechnical site investigation. The investigation was commissioned to establish the mechanism/s which may have contributed to the very low or reduced capacity of the anchors. Piling went to plan with limited problems, although the depths were not quite what was expected. It was only when Franki Africa started stressing that it observed some serious anomalies: some of the anchors failed to take the load. Shortly thereafter the additional investigation showed a change in ground conditions, tragedy struck. Almost the entire labour force was involved in an horrific road accident, stopping the contract in its tracks. Conquering their emotions, those who were spared from injury continued stressing anchors before a period of force majeure was exercised. Family members of those who had passed away were drafted in, retaining earnings for the families concerned. The contract was completed under a cloud of emotional stress and discomfort. 

PROJECT INFORMATION • Company entering: Franki Africa • Client: Nkomati Joint Venture • Project value: R89-million • Start date: November 2016 • End date: October 2017 • Main Contractor: Franki Africa

• Consulting Engineer: Arup • Project Manager: Nkomati

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