A STATE-OF-THE-ART SHORE CROSSING

Abstract

An insight is provided into the design and construction of the shore crossing of the export pipeline system for the Otway Gas Project in Western Victoria. The development of the Otway Gas Project, which is now underway, requires the installation of a 20-inch gas pipeline and a 4-inch glycol service line across the shoreline in the Port Campbell National Park along the Great Ocean Road, one of the major tourist attractions in Australia. An account is given of the landfall site selection process, the collection of required site data, the identification of geo-hazards, the development of a unique construction method based on a combination of retractable micro-tunnelling and horizontal directional drilling, and an outline of the construction challenges. These include the complex geo-technical conditions, the ever present high-energy Southern Ocean swell, and the environmental significance of the site. The design and construction work performed demonstrates that trenchless technology can successfully be applied for the installation of pipelines across shorelines provided detailed attention is paid to a number of design and construction aspects; bearing in mind that horizontal directional drilling design guidelines are generally limited with respect to these crossings.