en.Wedoany.com Reported - The core headrace tunnel of the San Gabán III Hydropower Station in Peru, constructed by Sinohydro Bureau 14 Co., Ltd., has been completed. With a total installed capacity of 209.3 MW, the hydropower station is located in the Andes Mountains of the Puno Region in southeastern Peru and has provided clean electricity to millions of Peruvians.
At the initial stage of project construction, multiple challenges were faced, including cross-border personnel movement, material allocation, and on-site coordination under the global pandemic prevention and control situation. The first batch of five key staff from Sinohydro Bureau 14 arrived at the site to carry out preliminary preparations and construction organization work. In response to conditions such as damp and hot tunnel interiors, narrow working spaces, and limited ventilation, the project team formulated a special epidemic prevention plan and construction organization plan to ensure construction progress.
The 8.5 km critical construction section of the latter half of the headrace tunnel was constructed using a full-face tunnel boring machine (TBM). In April 2022, the TBM became stuck when advancing into a fault fracture zone of the main tunnel. The project team took 72 days to free the machine, removing over 3,000 cubic meters of silt and gravel. This work was recognized by the owner and supervisor.
Facing challenges such as actual water inflow far exceeding expectations and increased workload due to design changes, the project department implemented standardized operations and shift handover systems to achieve continuous construction, installed WiFi and video monitoring systems inside the tunnel for visual dispatch, and conducted collaborative training for local and Chinese staff. The team adopted a TBM burial scheme inside the tunnel and designed a sliding device to shorten disassembly time; optimized the rail-mounted needle beam steel formwork trolley for rapid working condition switching; modified the TBM backup gantry as a concrete transfer platform; developed a dedicated lining end formwork system to reduce installation time to within 2 hours; and formulated a multi-stage water retaining sill and high-flow pump group drainage plan to handle excessive water ingress.
Over three years, the project team worked in knee-deep water and high geothermal environments. The project achieved a TBM monthly advance rate of 1,008 meters, concrete lining of 18 segments per month, and consolidation grouting exceeding 12,000 meters per month. The entire tunnel lining concrete achieved zero cracks, with a 100% first-time acceptance rate, and the tunnel filling target was met on schedule.
The San Gabán III Hydropower Station is an energy cooperation project between China and Peru under the Belt and Road Initiative, providing clean electricity to Peru.
