SANI PASS PHASE 2 ROADWORKS (KM13,6 TO KM25) T he Sani Pass, which was built in the 1950s, remains a problematic drive in 4x4 vehicles, with all the
• Company entering: Royal HaskoningDHV • Client: KwaZulu-Natal Department of Transport • Consulting Engineers: Royal HaskoningDHV in Joint Venture with Semenya Furumele Consulting • Main Contractor: Leomat Construction • Geotechnical Consultants: ARQ Consulting Engineers PROJECT INFORMATION
challenges, bad weather, and treacherous conditions that one would expect from a pass with an altitude of 2 876 m above sea level. In 2005, Lesotho and South Africa signed a cooperation agreement to improve commercial, social, and economic opportunities and accessibility between the SADC countries. Included in that agreement was the upgrade of Sani Pass to improve road drainage, prevent gravel loss, and limit erosion caused by high-intensity storms and flooding. As per the agreement, South Africa will surface the P318 up to Sani Top, and Lesotho will surface the road to Mokhotlong, with the ultimate goal of having a surfaced road all the way to Maseru. The project comprises three phases: • Phase 1 – From km 0.0 (junction with Main Road P126 from Himeville) to km 13.6 (Good Hope Trading Post). • Phase 2 – From km 13.6 to km 25.0 (SA Border Post). • Phase 3 – From km 25.0 to km 33.0 (summit at Lesotho Border Post). Phase 1 was completed approximately 12 years ago, Phase 2 was recently completed (the roadworks portion is included in this submission), and construction of Phase 3 is yet to begin. This submission is for Phase 2 of the Sani Pass upgrade project. It involves roadworks between the Good Hope Trading Store at km13,6 and the South African Border Post at km 25.0. The section of the P318 in question begins at km13.6 at an elevation of 1,577m. It generally follows the
southern banks of the Mkhomazana River as it climbs the escarpment in a series of steps with relatively long sections of moderate gradients interspersed with short sections of steep gradients. Temperatures in the Drakensberg range from -20°C to 35°C. The area's climate is defined by high annual rainfall of 1 800 mm and severe storms in the summer months. Winter brings cold temperatures and snowfall, and the upper sections of the Pass are frequently covered in ice. The existing gravel narrow track and drainage system could not handle the high-intensity water run-off on steep gradients, resulting in excessive scour and gravel loss. Gravel is a non-renewable resource, and good quality gravel is especially hard to come by in the Drakensberg. The eroded gravel eventually settles in local streams and rivers, particularly the Mkhomazana River, causing sedimentation and pollution in the lower reaches and negatively impacting aquatic biodiversity. Furthermore, the dust created by passing vehicles negatively impacted the biodiversity of the adjacent vegetation.
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21 st Best Project Awards 2022
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