How are cased concrete piles constructed?

Cased concrete piles are constructed by driving a steel casing into the ground and then filling it with concrete. This method ensures that the pile maintains its structural integrity during installation and provides a strong, stable foundation. The steel casing protects the concrete from environmental conditions and ground movement, ensuring that the pile can effectively transfer load to the surrounding soil.

The process begins with the driving of the steel casing, which penetrates through soil layers until it reaches a suitable load-bearing stratum. Once the casing is in position, concrete is then poured into the casing, filling it and allowing it to form a solid pile. This method can be particularly advantageous in scenarios where the soil conditions are challenging, as the casing can provide additional support and prevent collapse.

The other options do not correctly describe the process for constructing cased concrete piles. Ramming concrete directly into the ground does not involve casing and could lead to instability. Using wood as a casing could introduce issues related to durability and rot, while relying solely on plastic casings is not common practice in pile construction, especially for heavy-load applications where steel is preferred for its strength and stability.