Driven cast in-situ concrete piles are a type of foundation used in construction. They are constructed by driving a hollow steel or concrete casing into the ground until it reaches the required depth. The casing is then filled with concrete, either while still in position or after being withdrawn for reuse. This method results in a pile that is made up of both the casing and the concrete.
The use of a closed-ended casing during construction helps to prevent soil from entering the casing and mixing with the concrete, which could compromise the strength and integrity of the pile. The pile is constructed in situ, meaning that it is created on site rather than being prefabricated elsewhere and transported to the construction site.
Driven cast in-situ concrete piles are a popular choice for foundation construction due to their strength, durability, and ability to resist lateral and vertical loads. They are commonly used in a variety of structures, including buildings, bridges, and retaining walls. The details of the construction process are shown in the accompanying figure.
Fig.: Driven Cast In-Situ Concrete Piles Details
Paragraph 1: The installation process of driven cast in-situ concrete piles involves the use of a casing, which is filled with concrete and then compacted into the ground with a hammer. The compaction process ensures that the concrete has firm contact with the soil. However, it is crucial to avoid over-ramming the concrete or withdrawing the casing too quickly. Otherwise, there is a risk of lifting the upper portion of the in-situ concrete as the liner tube is withdrawn, resulting in a void or necking in the upper portion of the pile. To prevent this, good quality control of the concrete and a slow withdrawal of the casing are necessary.
Paragraph 2: Driven cast in-situ concrete piles can be a cost-effective solution for sandy, loose gravel, soft silt, and clay soils, particularly when a large number of piles are required. However, for small-scale projects, the on-site costs may prove to be expensive. Therefore, careful consideration of the project’s size and requirements is necessary to determine the feasibility of using this technique.
Driven Cast In-Situ Concrete Piles Construction Process
The process of construction of driven cast in-situ concrete piles are shown in figures below:
1. Permanent pile casing first made ready for driving
2. Pile casing is then driven into the soil
Fig.: Driving of Pile Casing
3. Reinforcement cage is then lowered into the pile core
Fig.: Reinforcement Cage placement in pile core
4. Concrete Pouring
The process of constructing driven cast in-situ piles involves pouring concrete into the pile core. This is done after the pile has been driven into the ground. The construction of these piles is achieved by first drilling a hole into the ground and then inserting a steel reinforcement cage into the hole. The pile is then driven into the ground using a pile driving machine. Once the pile has been driven to the required depth, concrete is poured into the pile core to complete the construction. This ensures that the pile is firmly anchored into the ground and can provide the necessary structural support. Overall, the construction of driven cast in-situ piles involves a series of steps that must be carefully followed to ensure the stability and integrity of the structure being built.
Fig.: Concreting of Driven Cast In-Situ Pile