Features:

- Suitable for composite formations from clay and sand to soft and hard, with high tunneling efficiency and low construction cost;

- With open, semi-open and closed modes, each mode can be converted to each other;

- Advanced and reliable cutterhead design and bauxite improvement system;

- Reliable main bearing, main drive seal and main drive reducer, long life and high safety factor;

- Safe and efficient PLC control system, real-time online monitoring and data acquisition.

Project Overview: The high-rise buildings along the tunnel are complex and the geological conditions are complex. There are karst and structural fracture zones distributed. The tunnel excavation sections are generally soft and hard, the filling material composition is messy, the rock quality is very different, and the local stone buds are prominent; the filling is extremely uneven, and the coarse sand and gravel are mixed. The karst water is extremely rich and the connectivity is good. The minimum design curve radius of the tunnel is 350m, the clay in the formation is very viscous, and the cutter head is prone to “sludge cake” phenomenon; the upper cobble layer is rich in groundwater, prone to spewing or ground collapse; crossing the railway station and track line, the underground pipe network is dense. , the requirements for ground settlement control are high.

Difficulties in engineering: clay mudstone, unconfined compressive strength 10MPa; structural fracture zone, open and soft surface is generally soft and hard, karst water is abundant; under the Xiangjiang River, sand pebble, sandy slate, soft and hard, there are Partial fault.

Equipment model and parameters: ZTE6250 earth pressure balance shield machine, excavation diameter Φ6250mm, total length 78m, cutter drive power 750kW, torque 4500 kNm.

Construction performance: The earth pressure balance shield machine of Tiejian Heavy Industry successfully completed the tunnel excavation work and was in good running condition. The maximum daily footage is 30m, the maximum weekly footage is 150m; the maximum surface elevation is no more than 10mm, and the ground settlement is small, which meets safety regulations.

Equipment users: China Railway 13th Bureau, China Railway 12th Bureau, China Railway 5th Bureau