The Civil Engineering Contractor February 2018 | Page 19

ON SITE The pipeline stretches across the wetland, waiting to be back-filled and rehabilitated. Drainage contract interesting facts and the underground material in the area. In terms of environmental procedures and requirements, Esor opted to cross the wetland by means of piling. This allows minimal damage, as the area is of high ecological importance owing to the different fauna/flora, which has conservational importance. Work on the wetland commenced in May 2017 with the wetland crossing at Area 23.   The scope of works of Esor, with civils subcontractor Khanyisa Civils and earthworks plant supplier Masemanzi Mining, was to strip the vegetation, excavate the material, and stockpile the material for later rehabilitation. Esor needed to construct a dump rock platform to access the area and afford stability. Once completed, Esor will install stormwater drainage and lay biddum over the rock area to ensure the wetland is not contaminated with G5 material. Once the platform was created, piling subcontractor Makarios’s piling crew began the 45, 10.5m-deep piling operations, which allowed Esor to work concurrently with the piling crews to install the structural steel elements — supplied by KTM Engineering — and lay and flange together the 500mm steel pipeline. The biggest challenge of the operation was the tight schedule of five months within which to complete the construction works before completing the rehabilitation of the wetland, and avoid the rainy season. The rehabilitation involved the full removal of the dump rock and G5 platform, the removal of temporary works protecting the wetland, and replacing the carefully removed and stockpiled topsoil.  The entire project is presently about 85% completed, Keevy says and points out that Esor’s project programme is almost finished, presently standing at 90% completion, with due completion date set at March/April 2018, with only piping to be completed. The operational life of the power station is expected to be 60 years. The total estimated cabling to be installed for Kusile is 5 300km. nn Main contractor: Esor Construction Full value of Esor work at Kusile: R2.8-billion  Main civil engineering works: Kusile Civil Works joint venture (KCW JV) Pipe supplier: Sebetsa Trading (HDPE) Length of pipe laid: 50km Concrete cabling trench: 11km Backfill: 250 000m 3 Volume of earth moved: Approx. 400 000m 3 Length of V-drain: 3.5km Dam-lining supplier: Aquatan  Size of dams: 35 000m 3 per dam Number of people on site at peak time (Esor): Approx. 1 200 Number of people on site at peak time (KCW): 6 000 CEC February 2018 - 17