Värähtöpaalutus

Värähtöpaalutus, also known as vibratory piling or vibro-piling, is a construction method used for installing piles into the ground. This technique relies on a vibratory hammer, also called a vibrator, which is attached to the top of the pile. The vibrator generates high-frequency vibrations that are transmitted down the pile. These vibrations cause the surrounding soil to temporarily lose strength and stiffness, allowing the pile to penetrate the ground with less resistance.

The process involves lowering the pile into the desired position. Once in place, the vibratory hammer is activated. The rapid oscillations of the hammer create shear stresses in the soil, liquefying or reducing the friction between the pile and the soil particles. This reduction in resistance enables the pile to be driven or vibrated into the ground to the required depth. Once the pile is installed, the vibrations are stopped, and the soil regains its strength, providing support to the pile.

Värähtöpaalutus is particularly effective in granular soils like sands and gravels, where it can achieve high installation speeds. It is also used in some cohesive soils, though its effectiveness can be reduced. The method is often chosen for its speed and relatively low noise levels compared to impact piling, although the vibrations themselves can be a concern. It is a common technique for various foundation applications, including buildings, bridges, and other infrastructure projects where soil conditions are favorable.