The pipe jacking, also called pipe ramming, guarantee the thrust by hydraulic jacks or bottom-hole pneumatic hammer is a no dig technology which consists in a controllable horizontal drilling on the vertical plane with the insertion of pipes (counter-pipe or pipe tube).
WORKING
Like all technologies, no dig allows the laying of underground pipes without performing open excavations for larger diameters but for smaller distances.
This technology is frequently used for the construction of rectilinear or sloping micro-tunnels, with diameters between 219 mm and 2000 mm, necessary for transversal crossings of roads, railway lines, and even raised canals.
Once the crossing is completed, the pipeline can be inserted into the counter pipe.
GENERAL INFORMATIONS
TECHNICAL FEATURES
– methodology with directional control also with laser pointer;
– straight track;
– plano-altimetric precision of the route.
AREAS OF USE
– according to hydrogeological considerations:
– above groundwater;
– under groundwater, with a well-point system.
– in soils even in the presence of sand and gravel.
INDICATIVE TECHNICAL PARAMETERS
– minimum optimal covering not less than 2.00 m;
– diameters dmin – dmax = 219-2000 mm;
– maximum driving length = depending on the nature of the materials, laying condition type of pipe laying system.
MAIN STAGES OF THE PIPE JACKING
THRUST CHAMBER
construction of the thrust chamber of the appropriate size for the type of system to be used, and depth foreseen in the design phase;
PUSHING YARD SYSTEM
positioning of the pushing yard system: guide frame placed at the axis of the track; and the first element to be inserted is prepared;
THRUST FORCE
the thrust force, through a distribution ring, is applied to the rear face of the pipe; when the first element is inserted, a second one is positioned behind it (with a male-female joint or with a weld) and proceeds with the depression;