Pipe Sizes: From 1050mm to 3000mm diameter
Pipe jacking is the installation of man entry steel, concrete, VC or Polycrete pipes using mechanical excavation and laser guidance for accuracy.
Depending on ground conditions either a rotary cutter or mechanical backhoe is used to remove the material. The spoil is typically removed from the tunnel using vacuum, conveyors and skips or continuous flight augers.
A steerable cutting shield is attached to the leading edge of the product pipe. Accuracy is monitored by a laser, and hydraulic rams are attached to the shield to allow steering in all directions.
Thrust is provided by hydraulic rams located in the launch shaft. The thrust forces are distributed over the circumference of the pipe by a thrust yoke, reducing the point loading of the hydraulic rams.
A new 6,000 tonne jacking system was manufactured by Tunnelcorp in 2013. This system is capable of being split into four independently operated 1,500 tonne jacking units or as one massive 6,000 tonne system through a central control console.