18 - Vibratory Hammers—Design of Piles

Abstract

Although many piles have been driven in clay soils using vibratory hammers, vibratory pile hammers are best suited for sandy soils. Vibratory hammers are less noisy and do not cause pile damage as compared with pile-driving hammers. One of the major problems of vibratory hammers is the unavailability of credible methods to compute the bearing capacity of piles based on penetration rates. On the other hand, pile-driving formulas can be used to compute the ultimate bearing capacity of piles driven with drop hammers. Vibratory pile-driving depends on pile and soil characteristics, elastic modulus of pile and soil (Ep and Es), lateral earth pressure coefficient (K0), relative density of soil (Dr), and vibratory hammer properties.