Excitation and Flexibility Effects on Dynamic Response of Cantilever Retaining Walls

A series of dynamic response analyses of cantilever retaining walls were conducted in order to assess the effects of ground shaking characteristics (amplitude and frequency) and wall flexibility on the seismically induced lateral earth pressures occurring on the walls. The investigation was focused on the seismically induced thrust and its application point on the wall stem. Idealized backfill-wall systems were modeled by finite element method. Results were compared with solutions obtained by pseudo-static approach of Mononobe-Okabe and pseudo dynamic approach of Steedman-Zeng. The analyses indicate that the acceleration amplitude of the horizontal ground motion is the major effective parameter on magnitude of the dynamic thrust acting on the walls. The difference between the dynamic thrust predicted by finite element and analytical methods becomes more significant for large acceleration amplitudes. Magnitude of the dynamic thrust calculated by finite element method reaches its highest value when the excitation frequency overlaps with the natural frequency of the backfill-wall system Numerical modeling study indicates a decrease in dynamic earth pressures for more flexible walls.