- Publication no: ABC2017-153-17
- Published: 26 April 2017
The $1.28 billion CityLink Tulla Widening project involves widening of a 24km section of three major Melbourne freeways from Melbourne Airport to Power Street including the western section of the CityLink tollway, Tullamarine and Westgate Freeways. The project aims to increase capacity by up to 30 per cent and improve safety. As part of the Bulla Road to Power Street design and construct section of the project, the existing CityLink southbound ramp (Ramp Z) is to be widened on the inside of the curve over its entire length to allow for one additional traffic lane. The widening work is to be constructed adjacent to live traffic on the existing Ramp Z, CityLink mainline southbound carriageway, and West Gate Freeway eastbound carriageway. The project consists of widening of 14 spans and 420 m of elevated structure and 60 m of earth retaining structure. The deck widening varies to a maximum of 4.4 m. The existing Ramp Z deck at Span 1 and Span 2 are 43 m long each and have a composite steel I-Girders connected to segmental concrete box girders of existing CityLink mainline southbound structure along western side and existing CityLink southbound exist ramp to Montague Street/ city (Ramp L) along eastern side. This paper will discuss the design and construction challenges encountered by the project team including spanning over West Gate Freeway eastbound carriageway at Pier 9 and Pier 10 of Ramp Z, positioning of Pier 1B under the existing Ramp Z mid-span, proposed construction sequences to avoid twist of kinked steel I-Girders in Span2. Major bridgeworks are currently underway, with construction expected to be completed by mid-2017.