Paalujärjestelmän

Paalujärjestelmän, often translated as pile system or piling system, refers to a structural engineering method used to transfer building loads to deeper, more stable soil layers. This is particularly important when the upper soil layers are weak, compressible, or unstable, such as soft clay, peat, or loose sand. Piles are long, slender structural elements driven or bored into the ground. They can be made of various materials including concrete, steel, or timber.

The primary function of a paalujärjestelmän is to resist the downward forces exerted by a structure and transmit them to a load-bearing stratum, typically bedrock or dense soil. This prevents excessive settlement and ensures the long-term stability of the building. The piles can resist loads through end bearing, where the pile tip rests on a strong layer, or through skin friction, where the surrounding soil exerts a frictional force along the pile's surface, or a combination of both.

The design of a paalujärjestelmän involves determining the type of pile, their size, material, spacing, and the required depth based on soil investigations and the anticipated loads. Common types of piles include driven piles, which are hammered or vibrated into the ground, and bored piles, which are created by excavating a hole and then filling it with concrete. The choice between these methods depends on site conditions, environmental considerations, and cost-effectiveness. A pile cap, a thick concrete slab, is typically constructed at the top of the piles to distribute the building's load evenly among them.