Silent piling or the ‘press-in’ technique is a non dynamic method for the installation of steel tubular or sheet piles.
It utilises hydraulic rams to push the piles into the ground and is commonly marketed as ‘silent piling’, which is vibration free. This type of piling has become increasingly popular in dense urban areas where piling noise and vibration can be an issue. The first press-in machine was developed in Japan in the mid ‘70s and in order to reduce the size of the piling machine, installation was based upon the reaction principle, derived from adjacent piles.
The machine derives the reaction required to install piles from gripping previously installed piles, to press-in subsequent piles at the same time. This allows the press-in machine to self walk along the pile top. These types of machines are termed ‘silent pilers’. VolkerGround Engineering is able to complete silent piling by utilising a variety of machine sizes, in a variety of soil conditions. We operate a Kowan Stillworker ZU-100 piling press, but are able to offer other types of machine through our selected partner suppliers.
In certain hard ground, cobbles and gravels may be present which could cause difficulties for silent piling methods. Water jetting and integral augering systems can be used simultaneously with most standard press-in procedures. The water jet system uses high water pressure to reduce the bulb of ground temporarily during the installation operation. The high pressure creates a pilot hole through the hard strata, allowing piles to push heavier particles out of the way. It also lubricates the pile to temporarily reduce skin friction between the soil and the pile.
The silent piling technique with integral augering implements the press-in piling with simultaneous augering, which breaks up the hard ground and removes bore spoil. This then allows the jack-in force of the machine to advance the pile through the loosened zone created by augering. This technique is termed the ‘super crush’ system.
VolkerGround Engineering has successfully completed a number of projects utilising this technique, within sensitive urban environments, for commercial and residential basement structures.