A machine from Australian TBM developer Terratec is to be used to complete 11.5km of tunnelling work at the Xe Namnoy hydroelectric project in Laos.
Terratec is to design and manufacture a Ø5.74m Hard Rock Double Shield TBM for the project's low pressure head race tunnel after being selected by project subcontractor Seli Overseas.
Xe Namnoy is being developed by main contractor SK Engineering & Construction Co, Ltd, with Seli Overseas subcontracted for tunnelling works. The project includes a diversion weir, two combined concrete and embankment dams, power tunnels and shafts, a penstock, open-air powerhouse, switchyard, tailrace channel, and a 230/500 kV transmission system.
The TBM to be supplied by Terratec will install hexagonal concrete segments and its CutterHead has been designed to bore through the two main formations along the tunnel, the 'Tholam Formation' consisting of mudstones and siltstones and the 'Champa Formation' including siltstones, sandstones and conglomerates.
