common pile type in many parts of the world, such as Scandinavia, is the
precast concrete pile. Precast concrete piles are commonly manufactured
in square and ranging from about 250 mm to about 450 mm, with a maximum
section length of up to about 20 m. Other pile sections exist and may
include hexagonal, circular, triangular and H shapes.
have generally been driven with a drop hammer of 3 to 4 tons, although
in recent years, hydraulic hammers have become very common for driving
precast concrete piles. I some countries, diesel hammers and occasionally
also vibrators are used. Maximum allowable axial loads can be up to about
1 000 kN. The length of pile sections is often dictated by practical considerations
including transportation, handling problems in sites on restricted area
and facilities at the casting yard.
piles can be constructed either in the factory or on site. The quality
of the pile is very much affected by the construction and production process.
A typical section of a Swedish precast concrete pile is shown.
precast piles without joints is a lengthy process. It requires breaking
down the projecting pile head to provide a suitable lap for the steel
reinforcement and casting concrete to form the joint. Piles can also be
connected by epoxy to form the joint. Good alignment of the pile sections
is required to prevent excessive bending stresses developing on subsequent
length can be equipped with prefabricated joints. Other splicing methods
commonly adopted include welding of steel end plates or the use of epoxy
mortar with dowels.
piles are not suitable for soil deposits containing a significant amount
of boulders. In such cases, the pile may be equipped with a pile
shoe, which protects the pile tip during hard driving.