Seismic performance of reinforced soil slopes with gabions and geobags as slope facings in shaking table test

Abstract

Reinforced soil technology is a preferred solution for addressing fill slopes in mountainous regions. Despite extensive research on the seismic responses of reinforced soil slopes under specific slope surface conditions, the comparison of the dynamic responses among reinforced soil slopes with varying slope facings remains unclear. In the current study, two sets of reduced-scale shaking table tests were performed on reinforced slope models with gabions and geotextile bags used as front panels, respectively. The acceleration response characteristics, slope surface displacement, crest settlement, earth pressure and geogrid axial force distribution of the two models were systematically compared to assess their performance under earthquakes. The results indicated that the acceleration amplification factors across the slopes for the two types of front panels differed slightly. The strongest acceleration response was observed at the slope surface, followed by the unreinforced soil zone, and the least in the reinforced soil zone. Under seismic loading, the peak displacement of the slope surface increased with slope height and peak ground acceleration, with the gabion group generally showing smaller peak displacements compared to the geobag group. Moreover, post-earthquake recovery of slope surface displacement exceeded 70 % for both groups. Both tested models displayed uneven settlement at the slope crest after the earthquake. The maximum cumulative settlement, which amounted to approximately 0.6 % of the slope height, was observed with the gabion group, which exhibited a greater crest settlement compared to the geobag group. Despite initial disparity due to the self-weight of slope facing material, both slope groups exhibited the same vertical earth pressure evolution with comparable growth rates under earthquake. Similar spatial distributions were also observed in the axial forces of geogrid, in which the geobag group showed higher increments but lower recovery capacity than the gabion group.