putkipaalut

Putkipaalut, commonly referred to as pipe piles, are a type of deep foundation consisting of hollow steel tubes driven into the ground to transfer loads from structures to the surrounding soils or bedrock. The term is used in Finnish civil engineering and in other contexts to describe tubular, pipe-shaped piles.

Manufacture and design: Pipe piles are formed from steel tubes that may be closed or open at the tip. They can be used as standalone piles or as sleeves for concrete, forming composite piles. Installation is typically by driving methods, using impact hammers (such as drop or diesel hammers), hydraulic or vibratory hammers, or, in some cases, jacking or pressing. Capacity is developed through end bearing, skin (friction) along the shaft, or a combination of both. Open-ended piles allow soil to flow through during driving, which can improve capacity in certain soils, while closed-ended piles may be preferred where end bearing on a harder layer is key or where corrosion protection is a priority.

Applications: Pipe piles are widely used in marine and waterfront structures, bridges, and building foundations in soft or variable soils. They can be driven through groundwater and loose sediments and are often employed in pile groups or as components of composite piles with concrete encasement or reinforcement.

Advantages and challenges: Benefits include relatively fast installation, versatility in different soil conditions, and good load transfer characteristics. Challenges include susceptibility to corrosion in aggressive soils, the need for protective coatings or coatings plus cathodic protection, noise and vibration during driving, and the requirement for proper design verification and load testing.

Design and standards: Engineering design follows local codes and standards for deep foundations, with emphasis on geotechnical investigation, corrosion protection, fabrication quality, and load testing to ensure long-term performance.