1. Foundations provide support for structures, transferring their load to layers of soil or rock that have sufficient bearing capacity and suitable settlement characteristics.
2. Very broadly, foundations can be categorised as shallow foundations or deep foundations
3. Shallow foundations are typically used where the loads imposed by a structure are low relative to the bearing capacity of the surface soils.
4. Deep foundations are necessary where the bearing capacity of the surface soils is insufficient to support loads imposed and so they are transferred to deeper layers with higher bearing capacity.
A pile cap is a thick concretemat that rests on concrete or timber piles that have been driven into soft or unstable ground to provide a suitable stable foundation.
2. It usually forma partof the foundation of a building, typically a multi-story building, structure or support base for heavy equipment.
3. The cast concrete pile cap distributes the load of the building into the piles.
4. A similar structure to a pile cap is a “raft”, which is a concrete foundation floor resting directly on onto soft soil which may be liable to subsidence
When should a pile cap be needed?
- Pile foundation is required when the soil bearing capacity is not sufficient for the structure to whithstand. This is due to the soil condition or the order of bottom layers, type of loads on foundations, conditions at site and operational conditions.
- A pile foundation consists of two components: Pile cap and single or group of piles. Piles transfer the load of structures to the hard strata, rocks or soil with high bearing capacity. These are long and and slender members whose length can be more than 15m