Seismic loads on a tall, cantilever retaining wall were studied using centrifuge modeling. An aluminum wall (55\u27 prototype) retaining dry, cohesionless backfill was subjected to two successive dynamic events. The backfill surface was horizontal and even with the top of the wall. The input motion was supplied via a servo-controlled, electro-hydraulic shake table. The input motion was roughly sinusoidal with peak horizontal accelerations of approximately 0.2g and 0.4g for the first and second dynamic events, respectively. The input motion frequency was 1 hz at prototype scale. Lateral earth pressures on the wall, wall displacement, and accelerations of the wall and backfill soil were measured. Pressure transducers were used to directly measure lateral earth pressures on the wall. The magnitudes of the lateral earth pressures were compared with values calculated using the Mononobe-Okabe method. Preliminary results indicate that calculated pressures are higher than the measured pressures
