Vibro Force & Amplitude Calculators

Units of Measurement:

Amplitude mm
Centrifugal Force kN
Eccentric Moment kg/m
Frequency rpm or vpm
Dynamic pile weights kg

Amplitude - Principles & Definitions:

It is important to have as much amplitude as possible to drive a pile on a given project. (Project factors limiting the size of the vibrator may include: vibration restriction, crane capacities and power requirements).

Also, when a pile is clamped to the vibrator, the mass of the pile must be included in the tota; vibratory mass, so amplitude decreases.

Therefore the size of the eccentric moment versus the total vibratory mass is most important. (Noting that larger moment can be achieved with more horsepower, larger bearings etc.)

Normally required lower limits for amplitude in different soil conditions are:

• 2 to 4 mm Easy, non-cohesive soils (e.g loose sands)
• 5 to 7 mm Average soil conditions
• 8 to 10 mm Highly cohesive soils (e.g stiff clays)

The general approach to vibrator selection is to determine beforehand what pile weight you have, and then calculate the amplitude of vibration from this using the characteristics of the vibrator you propose to use. Then relate the calculated amplitude to the known soil conditions as stated above.

If the amplitude is less than required for the soil conditions, go to a larger vibrator and re-calculate.