On 12 May 2020, the second earth pressure balance TBM jointly developed by CRCHI and Sinohydro Bureau 5 for Chengdu Metro Line 19 Phase 2 completed FAT in Changsha. The first TBM for Chengdu Metro was developed in April. The two TBMs belonging to 5th-generation TBM, with the excavation diameter of 8-9 meters, have the advantages of more convenient control, smoother personnel channels and higher generalization.
The TBM has a total length of 106m, a total weight of 1150t and a total power of 5050kw. The TBM has 350m small horizontal turning radius and 50‰ climbing ability, which is CRCHI first group of 5th-generation EPBM with excavation diameter of 8-9 m.
In addition to tunneling through Chengdu Airport, challenges exist in water-rich sand and pebbles, composite strata and low gas. CRCHI has targeted designs: Composite A / A+B grouting system, middle shield slurry injection system, wind gas and electricity closed-cycle control and intelligent control system.