Friction pile foundation work refers to the construction of a foundation system using piles that rely on friction between the pile and the surrounding soil to support vertical loads. This type of foundation is commonly used when the load-bearing capacity of the soil near the surface is insufficient to support a structure. Friction piles are driven or cast into the ground to transfer the building's load to deeper, more stable soil or rock layers.

The process typically involves:

1. Pile Installation: Piles, which can be made of various materials such as steel, concrete, or timber, are driven into the ground using specialized equipment. The piles are often long and extend into the stable soil or rock layer below the weaker surface soils.

2. Load Transfer: The load of the structure is transferred from the building to the piles, which in turn transfer it to the surrounding soil through frictional resistance.

3. Load Testing: Load tests may be conducted to ensure that the frictional resistance of the piles is sufficient to support the expected loads of the structure.