en.Wedoany.com Reported - The concrete placement for the rock anchor beams in the underground powerhouse of the Zhejiang Jiande Pumped-Storage Power Station was recently completed. The rock anchor beam is the core load-bearing structure of the underground powerhouse, and the completion of this process marks phased progress in the construction of the underground cavern group, creating conditions for the subsequent installation of the overhead crane and the main construction of the powerhouse.
The rock anchor beams bear the hoisting loads of heavy equipment for the future installation and maintenance of hydro-generator units, and their construction quality directly affects the long-term safe operation of the power station. The rock-anchored crane beams, which were concreted this time, are located on the side walls at elevations from -49.60 m to -52.40 m in the underground powerhouse, with a total length of 436 m along the upstream and downstream sides. The construction was carried out in 37 pours, using C30W8F50 concrete, with a total placement volume of 2,000 cubic meters. This process integrates smooth-wall blasting, rock bolting, concrete placement, and monitoring and measurement, involving numerous embedded components and high precision requirements, making it a critical link in the quality control of the underground powerhouse system.
In response to construction conditions such as intensive cross-operations in the underground caverns and stringent temperature control standards, the project department conducted multiple blasting tests during the excavation stage and optimized blasting parameters accordingly to ensure forming quality. After entering the concreting stage, concrete performance indicators were verified through process tests, and a combination of alternate-bay placement and parallel multi-bay operations was adopted to effectively control shrinkage cracks in the concrete.
During construction, the project management team strictly implemented the refined management process of "one design per pour, one briefing per pour, and one summary per pour." Technical personnel provided full-time on-site supervision, strictly controlling the mix ratio, vibration process, and internal temperature control. The project department coordinated and allocated resources, organized continuous operations, and successfully completed all concreting tasks despite disruptions caused by material transportation and cross-construction activities.
The Jiande Pumped-Storage Power Station, located at the foot of Wulong Mountain in Jiande City, is a daily-regulation pure pumped-storage power station, primarily tasked with peak shaving, frequency regulation, phase modulation, and emergency standby for the East China Power Grid. The station has an installed capacity of 2,400 MW, making it the largest in East China, and is equipped with six units, each with a rated capacity of 400 MW, generating an average annual output of 2.8 billion kWh.
Currently, the diversion facilities of the upper reservoir have been completed and accepted, the dam foundation excavation is basically finished, dam filling has commenced, and the on-site roads and auxiliary plants are largely in place. For the lower reservoir, the second-layer excavation of the main powerhouse cavern and the first-layer excavation of the main transformer cavern have been completed, and the rock anchor beam concreting is finished. The excavation of the upper horizontal pressure tunnel has been completed, the pilot hole drilling of the upper inclined shaft is underway, and the middle horizontal tunnel is progressing in an orderly manner. The GIL construction adit is currently under construction. According to the plan, by the end of the year, the upper reservoir dam will be filled to elevation EL680 m, the underground powerhouse will be excavated to the seventh layer, and the excavation of the main transformer cavern and No. 2 construction adit will be completed.
