Page 169 - Numerical Analysis and Modelling in Geomechanics

150 C.L.RAMSHAW AND A.R.SELBY

Figure 5.13 (a) Displacement-time and (b) force-time functions at the pile head
(computed=solid line, measured=dashed line.
Vibrodrivers
Pile installation by vibrodriver is fundamentally different to impact driving, the
installation being achieved by liquefaction of soils immediately adjacent to the
pile. The method is most effective in saturated fine sands. The vertical cyclic
force F(t) is sinusoidal in form, and the pile is excited into rigid body oscillation,
at the driving frequency, and with amplitude which is dependent on the total pile
mass and the soil resistance on the shaft and toe.
(5.18)