Bheri Babai Diversion Multipurpose Project
Surkhet District, Karnali Province, Nepal
Award of Merit
Owner Nepal Ministry of Energy, Water Resources and Irrigation
Design Firm & Structural Engineer Power China
Contractor, Civil & MEP Engineer China Railway Group Ltd.
Consultant Geodata Engineering S.p.A
TBM Supplier The Robbins Co.
Crews tunneled through the foot of the Himalayas for the Bheri Babai Diversion Multipurpose Project. Despite an 8.1-magnitude earthquake, border struggles between Nepal and India, an oil crisis, catastrophic floods, strikes and riots, the international team managed to complete the 5-meter-dia tunnel seven months ahead of schedule. To get it done, the team had to engineer for excavating through complicated and changeable geologic strata.
The overall development consists of three components: the headworks, the headrace tunnel and a powerhouse. China Railway Group Ltd. led the completion of the 12.2-kilometer-long tunnel portion of the project using a double-shield tunnel boring machine in the southern end of the Himalayas. Officials say this was the first tunneling project of its kind in Nepal.
Each hexagonal prefabricated concrete segment has permanent drain holes to reduce external water pressure. Internal water pressure is transferred to the surrounding rock. Together with the drain holes, the internal and external water pressure is dynamically balanced.
The tunnel diverts water from the Bheri River to the Babai River and will provide irrigation for 51,000 hectares of land.