Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12 Page 13 Page 14 Page 15 Page 16 Page 17 Page 18 Page 19 Page 20 Page 21 Page 22 Page 23 Page 241 The pipe jacking technique Pipe jacking/microtunnelling* is a non-disruptive method of installing utility tunnels and conduits by thrusting pipes through the ground as controlled excavation is undertaken at the face. Pipes manufactured in a variety of materials to include concrete, clay, grp and steel can be jacked and standard pipe diameters generally range from 150mm to 2,400mm, or greater when required. Jacking lengths achievable can be considerably in excess of 1km depending on pipe diameters, ground conditions and excavation methods. Drive lengths are only limited by practical engineering considerations and economics and drives either in a straight line or to a radius or a series of radii are readily achievable. Pipe jacking can deliver environmental benefits in excess of 75% as measured by reduced carbon emissions compared to disruptive open-cut construction, which requires considerably greater amounts of excavation and substantial backfill material. Long- term damage to existing installed infrastructure is also minimised. *Microtunnelling - originally used to describe the construction of fully automated non man entry pipe jacked tunnels in smaller diameters, the term is now also sometimes applied to fully automated pipe jacks in larger diameters which may be controlled from above ground. 4 An introduction to pipe jacking and microtunnelling 1 THE PIPE JACKING TECHNIQUE Typical pipe jacking arrangement Environmental benefits - carbon emissions reduced by up to 75% Undisturbed soil Undisturbed soil Imported backfill Surround bedding PIPE Carriageway PIPE JACKING OPEN CUT