The paper presents a unique finite element model-based investigation and development of a relationship between the seismic active and passive earth pressure and the movement of a rigid retaining wall. A hardening soil with small strain model with consideration of the Rayleigh damping has been adopted for modelling soil. Validation of the finite element model has been carried out by using centrifuge test results already available in the literature. Unique design charts have been proposed highlighting the relationship between the seismic earth pressure and the wall movement. It is observed that the seismic active earth pressure is independent of the seismic input motion and hence does not depend upon the wall movement during an earthquake, while on the contrary the seismic passive earth pressure is significantly affected by it. Comparison of the results of the present study with the Mononobe-Okabe and pseudo-dynamic methods clearly highlights that the latter overestimates the seismic earth pressure. The proposed design charts and other results provide an important cue to the design engineers.

This paper investigates the structural and global stability of a cantilever-type retaining wall under seismic loading using numerical modelling. A new and robust approach is proposed to compute the seismic earth pressure behind the stem and along a virtual plane passing the heel of the wall. The results show that under different earthquake characteristics and wall geometries, the seismic earth pressure forces may be out of phase, leading to different seismic responses of the wall. The critical scenario for the structural stability is observed when the maximum acceleration is directed toward the backfill soil, and the earthquake frequency content is close to the natural frequency of the wall. In contrast, the critical scenario for the global stability occurs when the maximum acceleration is directed with minimum frequency content. Further, the natural frequency of the wall does not affect the global stability of the wall. However, the duration of the applied earthquake acceleration does affect the global stability of the wall, whereas the structural stability remains unaffected by it. In contrast with the current understanding, the possibility of failure of a cantilever-type retaining wall by horizontal sliding is remarkably increased with time of the applied earthquake acceleration.

No abstract