A major milestone has been reached at the Xe-Pian Xe-Namnoy hydroelectric project in southern Laos with completion of the 11.5km long headrace tunnel excavation more than three months ahead of schedule.
Contractor Seli Overseas completed the excavation on March 18 using a Terratec 5.74m diameter H43 Double Shield Tunnel Boring Machine (TBM).
Mucking out with rolling stock, Seli achieved impressive production rates with the TBM during the course of the project – including a record-breaking single month advance of 1005m in July 2016 – allowing the contractor to finish excavation three and a half months ahead of schedule.
“This tunnelling experience has been very good,” said Dario Vizzino, Project Director for SELI Overseas. “The Terratec TBM is very powerful and has performed extremely well. I think it is proof of the quality of the TBM, the team and also all of the systems that we chose for this project.”
The tunnel drive finished underground in a TBM disassembly chamber that was excavated by drill and blast. The entire machine will now be dismantled and its components will be brought all the way back through the tunnel.
The Xe-Pian Xe-Namnoy Power Company's (PNPC) US$1.02 billion Xe-Pian Xe-Namnoy Hydroelectric Power Project is located in an isolated area of national park on the Bolaven Plateau, in the south of the Laos People’s Democratic Republic (PDR), approximately 35km northwest of the provincial town of Attapeu and 80km east of the larger Mekong River town of Pakse.