Construction World December 2018

Civil Engineering Contractors

CONSTRUCTION OF A THREE CELL BOX CULVERT AND EARTH RETAINING STRUCTURE STC3971 ON D1357 AT KM 5,56

T he purpose of this structure was to overcome frequent flooding of the existing section of roads which prevented traffic and if attempted, was life threatening to cross. One of the major challenges of the project was to work safely within the heavy rainfall periods but there were also numerous other challenges that were systematically overcome, resulting in one impressive constructed structure. Construction commenced in September 2016. Management of this project encompassed the usual facets such as monitoring productivity, quality control, budget control, material procurement, scheduling of panel deliveries, process management, effective The 21,5 metre tall culvert and earth retaining structure on the D1357 located between the towns of Impendle and Himeville on the Southern Drakensberg side of KwaZulu-Natal was truly an innovative and challenging project which was completed successfully in April 2018. The client was the Department of Transport, the engineers were D.E. consulting engineers and the contractor was Durant Civils.

communication, safety and environmental management and labour relations. One of the first major challenges during construction was the uncertainty of the terrain. Rock was discovered and since the structure commenced after the road works, lifting the structure was not an option and the rock had to be painstakingly removed to the required depth resulting in the programme slipping by six weeks. The culvert was relatively straightforward. However, the earth retaining structure was proving complex. Since there are not many double sided Reinforced Earth retaining structures constructed, fewer that are on a curve, and even less as tall as the one on the D1357, getting the right supervision for the job was key. The general foreman was a highly experienced and creative individual who designed a method of lining the panels along the slope by utilising everyday construction materials. Reinforced Earth retaining structures are complex, requiring material complying with mechanical and chemical specifications and eliminating aggressive materials that would cause corrosion of the reinforcing strips that may eventually lead to failure. 

PROJECT INFORMATION • Company entering: Durant Civils • Client: Department of Transport

• Contract value: R31 198 522 • Start date: 22 September 2017 • End date: 30 April 2018 • Main Contractor: Durant Civils • Principal Agent: D.E. Consulting Engineers

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