Repeated observations from recent earthquakes show that the vertical ground acceleration can be amplified significantly and even become greater than its horizontal counterpart in certain situations, raising great concern over the potential effect of vertical acceleration on engineering structures. This paper addresses this issue for quay walls using the pseudostatic approach. The earth pressure and the resistance of quay walls to sliding and overturning are investigated for various combinations of horizontal and vertical seismic loading. The results show that while the effect of vertical acceleration is insignificant on the active earth pressure on the quay wall, it should not be overlooked in the stability analysis of the wall.
Seismic stability analysis of quay walls: Effect of vertical motion