Koeberg Interchange
In efforts to relieve the incessant congestion on both the south and north bound traffic between N1 and M5 (Koeberg Road and Table Bay Boulevard), the extensive upgrade was implemented.
This project had to be segmented into phases and necessitated the joint efforts of both the City of Cape Town and the Provincial Government of the Western Cape.
The City of Cape Town owns the Table Bay Boulevard section of the N1 between the city centre and Salt River, while the N1 from Salt River to the R300 highway(including Koeberg Interchange) falls under the Provincial Government of Western Cape.
Some of the worst traffic congestion in Cape Town is experienced at the Koeberg Interchange, where the N1 and the M5 highways intersect. Designed and constructed prior to the tremendous increase in traffic, due to the arrival of many businesses, shopping and residential developments, it became necessary to upgrade this link to alleviate the traffic.
Construction
The joint efforts of both the City of Cape Town and the Provincial Government of the Western Cape caused the implementation of the infrastructural improvements and additions to be split into three phases.
Phase 1 comprises directional ramps connecting the M5 with the N1; an extra traffic lane on the N1 southbound thus widening the N1 northbound through Koeberg Interchange to three lanes; two extra traffic lanes on the N1 northbound after Koeberg Interchange; extra lanes on Table Bay Boulevard south and northbound; construction of a walkway deck and pedestrian paths; and widening of the bridge carrying Table Bay Boulevard over the decommissioned Paardeneiland rail line. Relocation of existing services and modifying existing structures including minor realignments; and the rehabilitation of both carriageways.
Subsequent phases will include implementation of the N1 BRT scheme; widening of the southbound carriageway of the N1 through the Koeberg Interchange from two to three lanes; and implementing the extra traffic lane on the southbound carriageway of Table Bay Boulevard between Koeberg Interchange and Marine Drive Interchange.
The Koeberg Interchange project is valued at R610 million (US $79.3 million), while the Table Bay Boulevard rehabilitation project’s contract value is R130 million (US $16.9 million).
For Phase 1, of Koeberg a total 37 piers are being constructed; 20 on ramps A and B (the N1 to M5 over bridge), which is 640m long and 10.7 m wide however ramp A is scheduled for completion this year. The remaining 17 will be on ramp B (the M5 to N1 over bridge) which is 690m long, 10.7m wide and is scheduled for completion in 2011.
Challenges
With the Koeberg project being the largest precast, prestressed U-beam project ever awarded in South Africa, the task of manufacturing, transporting and placing the precast U-beams was very challenging. Achieving this task meant the use of two cranes, one 850-tons with another slightly smaller crane 550- tons to place the U-beams. In all 27 five-beam spans averaging 35m in length and weighing about 70 tons each were placed. Erecting the beams was done mostly at night, when traffic deviations could be implemented.
Another challenge was the M5 viaduct. For a distance of 375m the viaduct was widened by 7.4 m by adding five prestressed T-beams on the one side atop new pier supports. This new deck section, along with ramps A and B constituted a total new cast deck area of 14 231m2.
PROJECT TEAM
| Principal Contractors | HEAD CONSULTANTS |
Paaden Eiland Joint venture ( Group 5 & Power) |
HHO Africa |
