The TBM, CREC Yongning, developed by the China Railway Engineering Equipment Group (CREG), is the first domestically developed large-diameter and large-inclination inclined shaft TBM.
“This marks a significant milestone in the successful application of TBM technology in the pumped storage industry in China and fills the technical gap in TBM inclined shaft construction within the country,” the company said.
Henan Luoning Pumped Storage Power Station is the largest pumped storage power station under construction in central China, with a total installed capacity of 1.4 million kW. The project initiated optimising the upper inclined shaft, the middle adit and the lower inclined shaft into a primary inclined shaft, and created a new approach for the construction of pumped storage power stations in China.
CREC Yongning constructed the No.1 diversion inclined shaft which is 927m long, with a dip angle of 36.236 degrees, and a buried depth of 184-684m. The geology is mainly moderately weathered fresh porphyritic granite and the tunnel passes through two fault fracture zones.
For the project CREG developed new technologies such as variable angle inclined shaft starting and split assembly excavation to adapt to complex working conditions, addressing problems such as large inclination anti-slip car and material transportation. The company says the excavation speed was continuously improved, from the initial daily advance of 3-5m to 8-10m, and finally achieving 16m.
CREG says the achievement has major benefits for the construction of large-scale pumped storage power stations, which has increased in China in recent years.
