A shake box, 4.27m long, 1m wide, and 1.37m high with a test section or inner
box (3.35m long x 0.94m wide x 0.94m high) and two end compartments (each 0.46m
long) was used to conduct the test program. The shake box is composed of two
boxes sharing the same longitudinal sides and base. The end walls of the outer
box are fixed while the inner end walls are fitted with roller bearings to allow
them to rotate to deform the sand mass from a rectangular to a parallelepiped
configuration (simple shear) under a base acceleration. The compartments were
used to collect sand during stopping and reversal of a sand spreader. The longitudinal
sides of the box were constructed from 2.54 cm thick plexiglass specially hardened
and treated to reduce interface friction. The shaker box is supported on rollers
running on steel I-beams fixed to the laboratory floor and displaced horizontally
by an MTS actuator and control system. The range of horizontal displacement
that could be applied was +7.65cm to -7.65cm and the range of frequencies was
1 - 1000 Hz. Only horizontal acceleration can be applied to the shake box in
the present design. Thus, in this paper, the generic term acceleration is used
to denote horizontal acceleration.