The world’s first batch of EPB Slurry dual-mode cross passage TBMs, jointly developed by CREG and China Railway Tenth Bureau, successfully passed the Factory Acceptance Test in the Shanghai base on 15 January 2022. The two TBMs will be used in the Hangzhou Airport Express Cross Passage Project.

The excavation diameter of the TBM is 3.29 metres. The TBMs will be used for the cross passage, with an inner diameter of 2.76 metres, between the West Lake Cultural Square Station of the Hangzhou Airport Express Line and the Hangzhou East Railway Station. There are a total of 5 cross passages, all of which are deep-buried cross passages, with the deepest cross passage at nearly 40 metres. The water and soil pressure reaches 5.4 bar, and the strata is mainly silty clay, and other highly viscous strata. The construction conditions are complicated, which presents higher requirements for the equipment.

The tunnel is designed as twin tunnel. The length of the tunnel is 6.7 kilometres, with a maximum burial depth of approximately 300 metres, and a maximum water pressure exceeding 5 bar. The strata consist mainly of clay soil, clay limestone, siltstone and sandstone fractures zone, etc. Additionally, the equipment needs to pass under historical and cultural monuments of the Cefalù area, which puts higher requirements on our construction equipment and technology.

The total length of the project is approximately 5 kilometres, with -6° downhill excavation slope, and a minimum turning radius of 60 metres. In order to improve the safety and efficiency of equipment excavation, CREG has developed a 6.03 metre diameter double-support hard rock TBM “Hongyuan”, which is equipped with a number of innovative technologies, which can effectively deal with stage changing and excavation problems under adverse geological conditions of faults and fractures.