equipment designed to align and hold piles in correct position and to drive the piles into the ground. Equipment of this type can also be used for extracting piles from the ground. Pile-driving equipment includes a weight-lifting device and a driver, which is usually mounted on a pile driver or on a truck, tractor, railroad platform, excavator, or crane hoist.
Pile-driving equipment is classified according to the principle used in operating the driver as striking, vibratory, or jacking. With striking equipment, a hammer is usually used as the driver. Such hammers can be diesel hammers or single-acting or double-acting steam hammers. Single-acting steam hammers are semiautomatic and deliver 30–45 blows per minute; the striking head weighs 3, 6, or 8 tons. Hammers of this type are used to drive reinforced-concrete piles into the soil. Double-acting hammers deliver 100–350 blows per minute; they are more efficient, have an enclosed body, and can work underwater at depths up to 20 m. Automatic diesel hammers deliver 50–60 blows per minute. Such hammers can be built from rods or tubes. Hammers built from rods can be light, with a striking head weighing up to 250 kg, or heavy, with the striking head weighing 2.5 tons. Pile-driving equipment with vibratory action includes vibratory drivers and vibratory hammers. Drivers with jacking action consist of a winch mounted on a self-propelled undercarriage. A special type of jacking driver utilizes both a winch and a vibratory driver. Pile-driving equipment is used in the construction of bridges and highways, as well as in industry and hydraulic engineering.
L. A. SOKOLENKO