Centrifuge Studies of Topographic Effects: Parametric Investigation

This article presents the results of a comprehensive geotechnical centrifuge experimental program to investigate topographic effects across a series of single-sided slopes. The experimental campaign considered a range of governing factors, including slope inclination and ground-motion amplitude, frequency content, and duration. The testing program was non-destructive, allowing the centrifuge models to be subjected to over 140 different ground motions. Clear evidence of topographic effects, including amplification and deamplification of ground motion, were observed. Topography modified the frequency content and amplitude of the ground motion such that at the slope crest (1) peak ground accelerations ranged from 50% less than to 200% greater than the free-field, and (2) ground-motion mean square frequency shifted by as much as 55%. Higher topographic amplification levels lead to a larger topographic zone of influence, which, on average, spanned a distance equal to the slope height (H) behind and 2H in front of (toward slope) the slope crest. Physical modeling in the centrifuge proved to be a powerful experimental technique for generating empirical data to analyze topographic effects in a systematic and repeatable manner.

Automated summary

This study used a geotechnical centrifuge experimental program to investigate topographic effects on single-sided slopes. The results showed that topography modified the frequency content and amplitude of ground motion, leading to significant changes in peak ground accelerations at the slope crest and determining the extent of the topographic zone of influence. The centrifuge proved to be a powerful experimental technique for systematically and repeatedly analyzing topographic effects.