The Block Vibration Test is a field test used to determine the dynamic properties of soil or rock, such as natural frequency, damping, and stiffness. It helps in assessing how the ground will respond to vibrations caused by machinery, construction activities, or seismic forces. By applying controlled vibrations to a test block and measuring the ground response, engineers can design foundations that safely withstand dynamic loads from machinery, seismic activity, or heavy structures.

The Block Vibration Test provides key dynamic soil/rock parameters that are crucial for designing foundations subjected to vibrations or dynamic loads. These include

Natural Frequency (fₙ) – The frequency at which the soil/rock tends to oscillate naturally. Helps in avoiding resonance with machinery or seismic loads.
Damping Ratio (ζ) – Measures how quickly vibrations are dissipated by the soil/rock. Essential for dynamic load analysis and vibration control.
Dynamic Stiffness (Kᵈ) – The resistance of the soil/rock to deformation under dynamic loading, used for machine foundation and seismic design.
Modulus of Subgrade Reaction (kᵈ) – Similar to static subgrade modulus but for dynamic loads; used in designing flexible foundations.
Amplification Factor – Indicates how vibrations from machines or seismic events are amplified or reduced by the ground.