Sliplining Tyers River Conduit Tunnels – Gippsland Water

Abstract

This project involved the sliplining of two 60 year old prestressed concrete tunnels with Glass Reinforced Polymer (GRP) pipe. The two tunnels are part of the Tyers River Conduit (TRC), the main transfer pipeline from the Moondarra Dam to the Latrobe Valley. The tunnels; Boola and Blairs are 1520mm internal diameter and 165m and 190m long respectively. The GRP pipes used were DN1200, SN15,000, PN6 with standard socket and spigot joints. Three water treatment plants supplying nine towns and the Australian Paper Mill (AP) receive water from the TRC. Boola tunnel was completed in six days and Blairs tunnel in 10 days, as planned and without any incidents. During this period water supply to the treatment plants and AP was maintained by a combination of operating a standby pump station, topping up AP storage and pumping back stored raw water from Buckley’s Hill Dam. The key challenge was to complete the works in the shortest possible time to reduce the downtime and minimise the risk of loss of water supply. The driver for the project was condition based Asset Renewal and minimisation of the risk that industry customers would seek compensation for damages for any loss should Gippsland Water not reasonably maintain water supply. The project had significant environmental constraints due to being located within the Tyers State Park. This paper discusses the planning, design, work methodology, the use of local contractors and in-house resources to achieve a successful outcome.

Techniques