Opportunity
Vietnam has experienced increases in electricity demand of over 15% per year. Song Bung 4, the first major hydropower project in Vietnam funded by the Asian Development Bank, was intended to meet increasing power demands while reducing reliance on fossil fuels.
The project involved the construction of a roller-compacted concrete dam 361 feet (110 meters) high, an intake structure, a headrace tunnel 2 miles (3.2 kilometers) long and 24 feet (7.2 meters) in diameter, a surge shaft 52 feet (16 meters) in diameter, and a powerhouse.
The steep and rugged terrain, isolated location, and a work site spread over a large area make this a particularly challenging construction site logistically. A tight timescale was constrained by rainy-season flooding. Clear communication was challenging in the languages used on site: Vietnamese, Chinese and English.
Solution
We were the lead firm responsible for construction supervision and contract administration duties. We also provided design review, assistance with procurement, resettlement advice and monitoring, and environmental management and monitoring.
Poor rock conditions on the left abutment required significant investigation, redesign, and a revised construction methodology.
Challenges were met by the development of good, open working relationships between the client, contractors, designer, and our site supervision team, and a proactive approach to problem solving.
Outcome
Our collaborative approach to solving the geotechnical problems at the left abutment contributed to significant savings in schedule and expense.
By working 24 hours a day on site, the team was able to place concrete at a rate of 2.6 million cubic feet (75,000 cubic meters) per month.
We helped transfer knowledge of international practices and standards in the areas of engineering, procurement, resettlement, and contract management to the client, our local counterpart staff, and the contractor.