The South African National Roads Agency SOC Limited
CONTRACT NO” NRA N.011-100-2013/1
REHABILITATION OF NATIONAL ROUTE N11 SECTION 10 FROM MIDDLEBURG TO LOSKOMDAM (km23,5 to km 53.4)
CONTRACT VALUE: R353,250,000.00
FINAL CONTRACT VALUE: R410 009 018.66
COMMENCEMENT DATE: 2nd FEBRUARY, 2015
CONTRACT PERIOD: 32 MONTHS
CONTRACT COMPLETION DATE: 28th SEPTEMBER 2017
The Project was located on the National N11 section beginning at km 3,40 outside of Middleburg (to the north) and ending at km 53,4 to the north of Loskopdam. It included but was not limited to the portion km 23,5 to km 53.4 as well as the new Keeroms River Bridge construction at km 6.54 and the walkway installation at Doornkop (km 34 – km 3)
Certain Construction Activities:
- The traffic accommodation for the roadwork’s construction.
- The upgrading of the existing roadway to include 2 * 3,7 m lanes and 2.5 surfaced shoulder (each side) giving a surfaced road width of 12,4 m.
- The adding of an extra large lane through Kranspoort by widening of the cuttings by blasting.
- The widening of the existing road prism. The cold in-situ recycling of the existing base and widened layer as a sub-base
- The asphalting of the major intersections and the Kranspoort Pass including the provision of rolled in chips.
- The provision of a 4 km length pedestrian walkway at Doornkop.
Pavement Design for all parts of the various roads
Pavement Structure on the N11
- Pavement seal using 19mm and 9.5mm pre-coated stone
- 150mm G1 Base.
- 200mm C3 cold in-situ recycled (CIR) sub base.
- 150mm G7 upper selected
- 150mm G9 lower selected.
Main intersections and Kranspoort Pass.
- Provide a 45mm asphalt wearing course with rolled chips
Bridges
- Bridge B 1167 @ km 6.54. Build bypass, demolish old structures and build new 3 span bridge (including new approaches on both sides)
- Bridge B 2136 @ km 28.90. Widen the bridge on both sides.
- Bridge B 1682 @ km 44.12. Widen the bridge at Kranspoort river.
- Bridge B 1749 @ km 51.93. Widen the bridge over the Canal.
- Bridge B 3611 @ km 53.50. Widen the bridge over the Olifants River on both sides and strengthen the beams and piers.
Other structures.
- Provide concrete barrier walls @ km 34.5 to km 38.1
- An arrestor bed @ km 37 to be constructed
SMALL Contractor Development, Training and Community Participation.
The South African National Roads Agency SOC Limited is committed to the implementation of Government’s policies and as such KPMM was expected to do the same.
KPMM adhered to these by during the construction period by:
- Implementing the policies of the Government’s Reconstruction and Development Programmes.
- The employment and creation of Targeted Black Enterprises.
- The implementation and arranging of generic, Engineering and entrepreneurial training programmes.
- The maximum utilisation of labour during construction.
Backfilling behind a Reinforced Earth retaining wall to support the arrestor bed.
Cutting No7 was the largest cutting on the project with 88,000m3 of rock excavation required.
The full quantity of G1 required for the contract was crushed from material obtained from this cutting. As there was no physical access to the top of the cutting development blasting was required in order to create the required access.
Cutting No6 was a very unstable cutting that needed to be secured by means of soil nailing and shotcrete. Mesh draping had to be installed at the crest and over the full length of the cut to secure potential loose rock.
Cut 6 protection in progress on RHS before commencement of the Reinforced Earth retaining wall on LHS. The start of Cut 7 can be seen in the distance just above the curve.
On site Crushing. All the material blasted in the cutting was hauled to the crushing site. All G9, G7, G5 and G1 material required on site was supplied from the project’s crushing site.
Constructed G1 base and prime.
Asphalt paving in progress over Olifants River Bridge.
Earth platform were created through the Olifants River and culverts installed to allow continuous water flow while the repairs and strengthening of the bridge were in progress.
The Loskop Dam.
