China Railway Engineering Equipment Group Co., Ltd (CREG) has been recently awarded to supply a Slurry TBM for Chunfeng Tunnel Project, Shenzhen. The machine is 15.78 meters in diameter and will be the first Slurry TMB of such large diameter to excavate in China.
 

The completed tunnel is designed to be an Expressway for cars travelling at 60km/h. It will be the first single-bore with double-decked interior providing four lanes and two continuous emergency parking lanes, three in each tube. Traffic on the two decks of each tube will run in opposite directions.

Chunfeng Project is one the most important municipal project for the purpose of easing the traffic congestion in Shenzhen megalopolis. The total tunnel length is more than 5000m, in which 3583m will be built by TBM. Tunnel will cross beneath Metro Line 9, Jibu River (ca. 50m width) and several high risky buildings etc. The settlement control will be a big challenge for the new machine. 

The TBM is expected to launch in 2018 and complete its tunnel in 2020.

TBM Specification

        Boring diameter: 15800 mm
       Max. working pressure: 8 Bar
       Drive power: 6300 kW (350kW*18)
       Nominal torque: 51130 kN∙m
       Max. torque: 69027 kN∙m
       Rotation speed: 0-2,25 rpm
       Thrust force: 24630 t
       Max. advance speed: 50 mm/min

To work with a TBM of this scale, there are a number of major technical risks ahead that need to be managed effectively to maintain safe excavation at 8 bar pressure and ensure water tightness. Yet CREG is very confident in doing a good job with its own reserve of experience and expertise.

A year ago, CREG received an order for one 15.03m Slurry TBM to bore the 3.05km long Su'ai Gulf subsea tunnel in Guangzhou. The tunnel comprises twin parallel tubes for six lanes in total (three in each tube for each direction). Each tube has a three-decked interior designed for exhaust tubing, traffic lane and cable-line run respectively from top to bottom. 

The giant TBM will pass through highly variable geology beneath the Su'ai Gulf. The strata range from clay to muddy soil; from coarse sand to weathered granite; and to mixed faces that include them all. 

The estimated water pressure is high – up to 6 bars. To deal with this, CREG developed a system for replacing cutting tools under normal atmospheric pressure. Moreover, the customized main drive is capable of telescopic movement and swinging in all directions to further ease the difficulty in changing disc cutters and to increase project productivity. 

The Gulf Tunnel project lies in Shantou's inner gulf between Haiwan Bridge and Queshi Bridge. The project plunges into the Su'ai Gulf on the west of the Shantou International Containers Terminal and the southwest of Longhu Canal. It then lands on the south bank on the west of Shantou Diving Natatorium.

The TBM is due to start excavation this autumn and the tunnel is scheduled to open for traffic in late 2019.

TBM Specification
        Drive mode: Electric
        Drive power: 5600kw
        Excavation diameter: Φ15030mm
        Shield diameter: Φ14980/14950/14920mm
        Rated torque: 45450KN.m
        Max. Torque: 59085kn.m
        Breakout torque: 63630KN.m
        Rotational speed: 0-2.5rpm
        Max. Thrust: 22220 T(350bar)
        Max. Advance speed: 50mm/min