Composite Piles are those piles of two different materials are driven one over the other, so as to enable them to act together to perform the function of a single pile. In such a combination, advantage is taken of the good qualities of both the materials. These prove economical as they permit the utilization of the great corrosion resistance property of one material with the cheapness or strength of the other.
The different stages in the construction of a composite piles having a timber pile at its lower part and precast concrete pile above are shown below. This type of composite pile is used with the object of achieving economy in the cost of piling work.
Another type of composite piles commonly used consists of a steel pipe or H-pile at the bottom and cast-in-situ concrete pile at the top. This type of composite pile is recommended in cases where the designed length of the pile works out to be greater than that available for the cast-in-situ type of pile.