Seismic response of gravity quay walls. I: Centrifuge modeling

Failure of gravity quay walls induced by earthquakes has been widely observed in the field. This paper studies the behavior of gravity quay walls under earthquake loading using data from three centrifuge tests. Failure modes similar to those observed in the field were replicated in centrifuge tests. It is shown that excess pore pressure generated in the backfill increases both the angle of failure wedge and the horizontal thrust on a retaining wall. Lateral displacement of a gravity retaining wall with dry backfill can be estimated using New-mark's method. However, for a retaining wall with saturated backfill, the presence of excess pore pressure makes it difficult to apply this type of calculation. Cyclic shear stresses and excess pore pressures induced by base shaking can lead to deterioration of soil strength and stiffness, which reduces the fundamental frequencies of wall vibrations. Implications for design are discussed.