Appin Road Widening

Design management for duplication of 2.2km of Appin Road with a new plank bridge to create an overpass for a koala crossing between Biobank and protected bushland.

INTRODUCTION

The Figtree Hill project sits on a 210 ha parcel of land and is located about 5 km south of the Campbelltown city centre. It is bound by Appin Road in the east, woodland to the north and farmland to the south and west. The development consists of the subdivision of land to create up to 1,700 residential lots, open space, parks and community facilities.

Lendlease is currently undertaking the staged upgrade of Appin Road. The initial stretch currently under construction (stage 1) consists of dual lane carriageway which extends south from Noorumba Reserve to a point approximately 850 meters north of Beulah Reserve and has currently been awarded to a Civil Contractor for the Construction works which is due to commence shortly.

Lendlease is now looking towards Works Authorisation Deed (WAD) 2 works which includes updating the existing Stage 2 design for the Southern signalised intersection, assessing the intersection configuration and updating it to cater for the continuation of the widening of the existing Appin Road including the construction of new bridge through Beulah Reserve which will also serve as a Fauna Underpass for the Koala population.

THE CHALLENGE

The challenge was to ensure that the constructability of the new road duplication and bridge did not affect the existing Appin Road during the construction phase. Long term closure of any lanes was not acceptable to Transport for NSW (TfNSW). Along the proposed alignment there was 3 additional constraints being the Sydney to Melbourne Optic Fiber line that would require relocation and 2 Culturally significant trees. Multiple bridge type options were proposed and workshopped with our design partners with the most optimum solution chosen which was a 2 x 18m plank bridge.

THE APPROACH

Due to the short time frame for the design it was imperative to ensure early engagement was undertaken with Transport for NSW. Discussions with their Subject matter Experts to understand their concerns early to address and engineer out has been critical to ensure the project stayed on program.

Numerous workshops have been held with TfNSW to discuss various topics such as Constructability, Health and safety, Environmental and long term maintenance of the bridge and koala furniture that is being implemented into this development.

RESULTS AND BENEFITS

From our involvement in Stage 1, the lessons learnt have been able to be implemented early into this project which is Stage 2. Items such as Fauna Fencing, Koala grids and Koala furniture designs have been readily transferrable to this project reducing some of the approval timeframes.