Pipe Jacking

Slurry Balance Pipe Jacking Machine

The slurry balance pipe jacking machine uses pressurised slurry to balance face pressure while jacking purpose-designed pipes from a launch shaft toward the reception point. CRCHI configures the cutterhead and slurry circuit to suit silt, sand, mixed soils, hard rock and high-water-pressure ground, making the machine a flexible micro-tunnelling option for urban cable, water supply, drainage, gas and utility-corridor pipelines.

Used inPipe-Jacking Package

Slurry Balance Pipe Jacking Machine cross-section — Cross-section

Numbered callouts on the cross-section, in order from the cutting face back to the launch shaft.

1.Cutterhead
2.Main drive
3.Shield
4.Hydraulic system
5.Slurry feeding pipeline
6.Slurry pump
7.Slurry discharge pipeline
8.Back-up system
9.Thrust device

Working principle

A rotating cutterhead equipped with cutting tools is pressed against the tunnel face to cut ground or rock. The excavated material enters the excavation chamber where it mixes with mud to form slurry. A slurry feed pipe delivers fresh slurry to the face and a slurry discharge pipe carries the muck-laden return back to a separation plant on the surface, which gives long-distance jacking a clean, contained spoil circuit.

A jacking device installed at the launch shaft, with optional intermediate jacking stations along the pipe string, pushes the shield and the specially designed pipes through the ground. Articulation joints and steering cylinders hold line and grade through curves; an air-cushion chamber and pressurised man lock allow cutter inspection and changes under normal pressure. Standard components on the machine include the cutterhead, main drive, shield, hydraulic system, slurry feeding pipeline, slurry pump, slurry discharge pipeline, back-up system and thrust device.

Features

Cutterhead configured per ground type: standard or composite cutterhead for soft and mixed ground, rock cutterhead with disc cutters for hard rock

Slurry pumps and a closed slurry circuit handle muck removal, keeping the working environment clean and supporting long-distance jacking

Articulation joints and steering cylinders provide accurate turning on curved alignments

Air-cushion chamber and pressurised man lock allow cutter changes under normal pressure

High-precision guidance system holds line and grade through the drive

Heavy-duty main bearing, main-drive seals and reduction gearbox deliver high torque, long service life and high safety

Reference projects

Water diversion project
Location
Qatar
Diameter
1,130 mm
Machines
1
Water diversion project
Location
Qatar
Diameter
3,060 mm
Machines
1
Shenzhen water drainage tunnel
Location
Shenzhen, China
Diameter
2,710 mm
Machines
1

Project	Location	Diameter	Machines
Water diversion project	Qatar	1,130 mm	1
Water diversion project	Qatar	3,060 mm	1
Shenzhen water drainage tunnel	Shenzhen, China	2,710 mm	1

Applications

Urban cable tunnels, water supply and drainage tunnels, gas pipelines, underground passages and utility corridors. Configured per project, with the cutterhead and slurry circuit matched to silt, sand, mixed soils, hard rock and high-water-pressure ground. The most prominent international reference is the Qatar water diversion project, with two CRCHI machines supplied for the same programme, alongside drainage and water-supply deployments across Chinese metropolitan markets.

Configuration and engineering

Every CRCHI TBM is engineered to project. Shield diameter, cutterhead geometry, drive power, segmental ring design and back-up arrangement are configured to the alignment, ground conditions and water pressure of the drive. Project-specific scope beyond the standard envelope is engineered to brief, and where a drive calls for it, a machine is developed from the ground up. CRCHI Australia is the engineering, commercial, commissioning and aftermarket point of contact for Australian projects.