Tunnelling is a key component of hydro projects worldwide. IWP&DC catches up with several companies to find out how their underground work is progressing
Recent tunnelling assignments for Vesley & Associates of Queensland, Australia include the Agbulu hydro power project in the Philippines. The company’s work for this included research and estimates for the future project which comprises a 230m high concrete face rockfill dam, with underground power house, associated tunnels, development of a quarry and construction of a 30km access road.
The company provides a service for various civil and mining projects to contractors, design firms and project owners. Ongoing services include assistance in project start up, planning, procurement, dealing with contractual matters and generally providing practical solutions to construction and design problems that need to be faced.
Vesley & Associates has also been looking at a proposed small hydro power plant in Papua New Guinea which would supply power to a mine. Tunnelling is seen as the preferred option as an alternative involves a large diameter (approximately 2m) pipeline located on the surface, which would have to be helicoptered in by heavy-lift Russian helicopters that operate in the country.
The main problems for the helicopters would be the dramatic reduction of lift with height; as cloud or fog suddenly appear in the valleys. Other difficulties include the lack of horizontal or flat storage areas in the region.