Construction World December 2016

OR TAMBO GAUTRAIN PLATFORM EXTENSION

The GRRL was developed as a public private partnership concession and includes a 15-year maintenance and operation period after completion of construction. This concession was awarded to the Bombela Concession Company (BCC). As part of the maintenance and operation of the Gautrain system, the BCC recognised the need to extend the station at ORTIA in order to allow for better commuter access at this location. The design and construction of the station extension contract for ORTIA was awarded to Stefanutti Stocks in April 2015. Stefanutti Stocks employed SMEC South Africa as their design consultant for the works. The ORTIA station extension project’s scope of works included the detailed design and construction of a length of approximately 55 m of extended station platform. The extension now allows passengers access to four train carriages instead of the previous two carriage access system. The principal challenge between the new station installation and the previous installation is that the current installation has been constructed and erected whilst the Gautrain remained fully operational. This resulted in numerous challenges for the erection and design team. The main challenge that was encountered was how to safely lift the 20 t platform slabs a height of 25 m above ground level, over the 25 kV live train line. Various options were considered by the contractor, including the use of various mobile and fixed crane types and even a moving vierendeel gantry frame, which would have required a rail to be installed in the adjacent road. The adopted solution was to use a fixed in place heavy lift crane (the largest in Africa) which met the load and lever arm requirements for lifting the heavy slabs into place on the southern side of the viaduct. In order to mitigate the risk associated with working adjacent to a live rail line, the design of the station roof had to be revised so that it could be installed in three sections. This is because the construction works could only occur over one track at a time after the OHTE had been switched off and removed and safety hoarding had been erected between the two tracks. The Gautrain Rapid Rail Link (GRRL) is designed for the rapid movement of commuters between Johannesburg, Pretoria and the OR Tambo International Airport (ORTIA) in Gauteng.

Project information • Company entering: Stefanutti Stocks Civils • Client: Bombela Concession Company • Start date: 30 May 2015 • End date: 23 May 2016 • Main contractor: Stefanutti Stocks Civils • Principal agent: Bombela Concession Company • Project manager: Turner and Townsend • Quantity surveyor: Stefanutti Stocks Civils • Consulting engineer SMEC South Africa • Subcontractor: Tass Engineering • Subcontractor: ITAL Concrete • Project value: R80-million

This allowed one track to remain operational whilst the overhead traction equipment was transferred from an existing mast support to the future roof support position. During construction the section of catenary from the ORTIA departure building to the second OHTE mast had to be removed. The horizontal tension force in the catenary after the second mast therefore had to be resisted.

One of the goals during the construction period of this station was to complete the project without impacting or changing the environment. Changes in the environment in this project entailed, (a) train traffic schedule, (b) cars and pedestrian working and travelling around the construction site and (c) car users parking for long term periods. This goal was achieved and the construction was completed without any incident or disruption to the environment. Nightshift engineering work was restricted to minimum noise. Pollution of dust was not allowed. During the demolitions, concrete walls were soaked with water and protective shield installed to prevent dust pollutions. This project was executed inside the airport premises, leaving the contractor with just ACSA and the city lodge hotel as the main stakeholders involved. OR Tambo is a key national point for South Africa. With thousands of passengers from all over the world travelling or transiting through this airport, the aesthetics and quality of finished work was exquisite.

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2 16 BEST PR O JECTS

DECEMBER • 2016