Utility Tunnelling: Pipe Jacking - Part 1

Lubrication of the annular space

Automatic grouting via injection nozzles inside the pipe string (3)

The number and arrangement of the injection nozzles per lubrication station are usually constant. In addition to the control of all existing valves, it is possible to change the positions of the injection nozzles in the cross-section at successive lubrication stations in order to realize an almost uniformly distributed lubricant injection at the pipe circumference [Schoesser2013].

A lubrication station consists of three to four injection nozzles distributed over the circumference which are connected to each other via a ring line. The opening time of the valves is 1 min. In the case of four injection nozzles, only two injection nozzles are open at a time; either nozzles 1-3 or nozzles 2-4. Viewed over the longitudinal section, the lubrication stations are alternately lubricated via nozzles 1-3 or 2-4 [Schoesser2013].


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