Paalfunderingen

Paalfunderingen (Danish for pile foundation) are a type of deep foundation used to transfer structural loads from a building or structure to deeper, more stable soils or to bedrock. They employ slender load-bearing elements, called piles, which are driven into or drilled into the ground and connected to the structure through a pile cap. Paalfunderingen are chosen when surface soils lack sufficient bearing capacity or when settlement must be tightly controlled.

Piles can work by different mechanisms. End-bearing piles transfer load primarily to a hard layer at depth, while friction piles transfer load through skin friction along the pile length in surrounding soil. Piles are commonly made of concrete, steel, or timber and can be precast and driven, cast-in-situ (bored or drilled shafts), or a combination of methods. Groupings of piles, linked by a pile cap, spread loads from the superstructure among multiple piles to increase total capacity and control settlement.

Design and construction involve geotechnical analysis and verification. Capacity is assessed by static methods, dynamic testing, or pile load tests; settlement criteria and group effects for pile groups are considered. Installation methods include hammer driving for driven piles or drilling for cast-in-situ piles, sometimes with jetting or vibration. Quality control includes pile integrity testing and monitoring of grout or reinforcement in cast-in-situ piles. Timber piles require protection against decay and moisture.

Applications span buildings, bridges, and offshore structures, particularly in variable or poor surface soils. Advantages include suitability for weak soils, high vertical loads, and controlled settlements. Limitations include higher cost and longer construction time, noise and vibrations from driving, and the need for thorough geotechnical investigation and precise coordination with superstructure design.