en.Wedoany.com Reported - On July 9, the first layer excavation and support work for the main transformer cavern of the State Grid Xinyuan Hunan Miluo Yuchi Pumped Storage Power Station, constructed by China Energy Engineering Group Gezhouba Group, was successfully completed, marking a new phase in the main construction of the underground powerhouse cavern group.
This power station is a key energy infrastructure project and a major livelihood project in Hunan Province. Once completed and put into operation, it will undertake core functions such as peak shaving, frequency regulation, phase modulation, energy storage, system backup, and black start for the Hunan power grid, providing critical support for the safe and stable operation of the provincial power system. According to estimates, after commissioning, the project will reduce raw coal consumption by 426,000 tons annually, cut carbon dioxide emissions by 1.93 million tons, and directly decrease new energy curtailment by 1.44 billion kWh, helping to optimize and upgrade Hunan Province's energy structure.
As the core control cavern of the underground powerhouse and water conveyance power generation system section, the main transformer cavern faces multiple construction challenges. The cavern has a large burial depth and complex geological conditions, traversing multiple sections of fractured rock layers and fissure development zones along its route, posing risks such as poor surrounding rock stability, prominent high ground stress, and difficulties in ventilation and smoke exhaust. Additionally, the dense layout of construction spaces around the cavern and high-frequency cross-operation of multiple processes impose high requirements on the precision of surrounding rock support, blasting safety, and refined full-process control.
Facing these challenges, the project team, focusing on key milestones, proactively planned the overall construction layout of the underground cavern group in advance, streamlining the entire process chain including excavation, support, mucking, and ventilation. By optimizing drilling and blasting parameters and surrounding rock support schemes, and precisely allocating personnel, machinery, and material resources, they ensured orderly progress in all construction stages.
To address geological issues such as surrounding rock deformation and rock mass water seepage, the project team applied core technologies including advanced geological forecasting, millisecond controlled blasting, and combined bolt-mesh-shotcrete support, while simultaneously implementing a safety grid management and quality refined control system. This approach resolved construction difficulties such as deep cavern surrounding rock stability and multi-process cross-interference from a technical perspective, and upheld safety and quality standards from a management perspective, ultimately achieving safe and efficient cavern excavation.
In the next step, the project team will advance the remaining construction of the underground powerhouse cavern group, focusing on core tasks such as concrete pouring for rock-anchored beam, excavation of headrace and tailrace tunnels, and main structure construction of the tailrace gate chamber. They will optimize resource allocation and strengthen full-process safety and quality control to support the timely commissioning of the power station and contribute to Hunan's green energy transition.
