A pile driver is a mechanical device used to drive piles into soil to provide foundation support for buildings or other structures. The term is also used in reference to members of the construction crew that work with pile-driving rigs.
One traditional type of Pile driver includes a heavy weight placed between guides so that it is able to freely slide up and down in a single line. It is placed upon a pile. The weight is raised, which may involve the use of hydraulics, steam, diesel, or manual labour. When the weight reaches its highest point it is then released and smashes on to the pile in order to drive it into the ground.
From an army manual on pile driving hammers:
Specialty equipment which installs piles using hydraulic rams to press piles into the ground. This system is preferred where vibration is a concern. There are Press attachments that can adapt to conventional pile driving rigs to press 2 pairs of sheet piles at a time. Additional types of Press equipment sit on top of existing sheet piles and grip onto previously driven piles. This system allows for greater press-in and extraction force to be used since more reaction force is developed. The reaction based machines operate at only 69dB at 23ft allowing for installation and extraction of piles in very close proximity to noise and vibration sensitive areas where traditional methods may threaten the stability of existing structures.
Such equipment and methods are specified into portions of the internal drainage system in the New Orleans area after Hurricane Katrina as well as many projects around the world where noise, vibrations and limited access are a concern during the engineering design and construction phases of the project.
Vibratory pile hammers contain a system of counter-rotating eccentric weights, powered by hydraulic motors, and designed in such a way that horizontal vibrations cancel out, while vertical vibrations are transmitted into the pile. The pile driving machine is lifted and positioned over the pile by means of a crane, and is fastened to the pile by a clamp and/or bolts. Vibratory hammers can either drive in or extract a pile - extraction is commonly used to recover steel "H" piles used in temporary foundation shoring. Hydraulic fluid is typically supplied to the driver by a diesel engine powered pump mounted in a trailer or van and connected to the driver head through a set of long hoses. Vibratory pile hammers are often chosen to mitigate noise, as when the construction is very close to residence or office buildings, or when there is not enough vertical clearance above the foundation to permit use of a conventional pile hammer (for example when retrofitting additional piles to a bridge column or abutment footing). Hammers are available with several different vibration rates, ranging from about 1200 vibrations per minute to about 2400 VPM; the vibration rate chosen is influenced by soil conditions at the site and other factors such as power requirements and purchase price of the equipment.
WIPO ASSIGNS PATENT TO KIMYO HEAVY CONSTRUCTION FOR "ELECTRIC WALKING PILE DRIVER FOR CONSTRUCTING UNDERGROUND RETAINING WALL" (SOUTH KOREAN INVENTOR)
Sep 13, 2010; GENEVA, Sept. 14 -- Publication No. WO/2010/101315 was published on Sept. 10. Title of the invention: "ELECTRIC WALKING PILE...
Wipo Publishes Patent of Ir Dr Ong Chin Chai for "Adjustable Raked Pile Driver Using the Push Pull Method" (Malaysian Inventor)
Mar 01, 2013; GENEVA, March 1 -- Publication No. WO/2013/028055 was published on Feb. 28.Title of the invention: "ADJUSTABLE RAKED PILE DRIVER...