Dynamic behavior of reinforced slopes: horizontal acceleration response

摘要

ABSTRACT: Shaking-table tests on plane-strain geosynthetic-reinforced model slopes using stepwisenintensified sinusoidal pulse loads with specific frequencies were conducted to investigate theninfluence of peak ground accelerations, wave frequencies and plastic slope displacements on thenhorizontal acceleration response of the slope. A comparative study on the crest response behaviornsuggested that the tests using pulse loads give useful insights into the dynamic behavior of soilnstructures subjected to earthquake loads. Test results indicate that both the horizontal accelerationnresponse at the crest and the lateral slope displacement are influenced by the horizontal peaknground acceleration, the wave frequency, and the cumulative permanent displacement of the slope.nAmplification factors at the crest of the slope are functions of input wave frequencies; theyndecrease exponentially with increasing input horizontal peak ground acceleration. Transitions fromnan amplification state to a de-amplification state at the slope crest occur at certain levels of inputnground accelerations, which are associated with the development of major slip planes in the slopenmass (or with noticeable slope displacement). It was found that a ratio between the plastic slopendisplacement and the total slope height (Dmax/Ht) of the order of 0.42–5.9 3 10u00012nis relevant tonthis amplification–deamplification transition. A practical implication of these observations is thatnthe resonance acceleration of the slope is a major factor that needs to be considered in seismicnstability analyses of reinforced slopes with a small plastic slope displacement of Dmax/Ht u0002 2.5 3n10u00013n; it does not need to be considered in the seismic stability evaluation for reinforced slopesnwith plastic slope displacements of Dmax/Ht ¼ 5.0–5.9 3 10u00012n.