How do friction piles support loads?

Friction piles support loads primarily through resistance from the soil along their sides. These piles are embedded into the ground, and as they are driven deeper, friction develops between the surface of the pile and the surrounding soil. This frictional resistance allows the pile to effectively transfer the load from the structure above to the surrounding soil, thereby providing stability and support.

The effectiveness of friction piles relies on the soil characteristics—its cohesion and compaction—as well as the surface area of the pile in contact with the soil. This interaction is crucial, particularly in situations where bedrock may not be accessible or when the structural loads exceed the capacity of end-bearing piles.

Understanding this mechanism is essential for engineers when designing foundations, as it influences decisions on pile length, type, and the expected load capacity based on soil characteristics.