pile hammer is between 3 and 10 t, and large hydraulic hammers whose weights
exceed 10 t. Small hydraulic hammers are suitable for steel and concrete piles with
smaller cross-sectional sizes; medium and large hydraulic hammers are suitable for
pile foundation construction of port wharf, high-rise buildings, bridges, and other
projects. Foreign hydraulic hammer series products have been formed to meet the
needs of various foundation constructions.
In recent years, the research and development of hydraulic hammers have been
carried out in the domestic pile machinery industry, but there are not many large
tonnage and high-performance hydraulic hammers, which cannot meet the growing
engineering needs. For this reason, foreign hydraulic hammers have been introduced and adopted in domestic foundation construction. Domestic enterprises have
successively studied and developed hydraulic hammers. This section compares and
analyzes the hydraulic system characteristics, performance, strike frequency and
strike energy of several typical foreign hydraulic hammers.
12.1.1 Hydraulic System of Typical Hydraulic Pile Driving
Hammer
12.1.1.1 British BSP Single Acting Hydraulic Hammer
British BSP Company produces a single acting hydraulic hammer. Figure 12.2
shows the hydraulic system and outline of CGL370 hydraulic hammer. During the
rising stage of the pile hammer, the electromagnetic directional valve 9 is electrified
Fig. 12.1 Pile driver for
lifting heavy objects by rope
in the fifteenth century
270
12 Pneumatic–Hydraulic Pile Driving Hammer