Page 177 - Numerical Analysis and Modelling in Geomechanics

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

Figure 5.20 Vertical velocities at 5.7 m, 14.5 m and 32.9 m, vibrodriving at Second

Severn Crossing (computed=solid line, measured =dashed line).

estimates of the transient or cyclic response of structures, it may be essential to
recognise that the presence of a stiff structure will modify the ground waves; the
structure will not deform to follow the transient free-ground movements.
Transient response of three conceptual structures is now demonstrated briefly,
with respect to a simple rectangular steel portal, a brickwork wall, and a buried
gas main. Appropriate mesh forms are described.