2018 32 Paper: Gordon Intake Managing an ever-expanding critical structure

The Gordon Power Station intake tower is a 75m high cylindrical concrete structure that controls the water flow to the underground power station below. The intake tower is affected by an Alkali-Silica Reaction (ASR) causing ongoing expansion of the concrete, and to date the tower has increased in diameter by 13mm since construction. This growth has significant implications for the 8m diameter cylindrical intake gate installed at the base of the tower that is designed to close and seal against full-flow of 450m3/s in just 18 seconds.
The intake gate is operated by a 7m-long submerged hydraulic servomotor located at the bottom of the tower. The servomotor's condition has deteriorated faster than expected and due to the critical nature of the servomotor, and challenges with accessing it for inspections and maintenance, it has been necessary to replace the cylinder only partway through its expected lifespan.
This paper will discuss the unique solutions used to manage the challenges associated with the Gordon Intake Structure and ensure the ongoing performance of this critical asset.

• Author: Andrew Koolhof
• Exchange: 2018 - Albury AGL
• Company: Hydro Tasmania
• Topic: Asset Condition, Asset Management, Civil, Dam Safety, Trash Racks, Tunnels
• Key Words: ASR, Asset, Concrete, Gates, Guard Gate, Hydraulics, Maintenance, Modeling, Protection, Repair, Trash Racks