Shaking Table Tests on Dynamic Characteristics of Two-stage Reinforced Soil-retaining Wall
【Abstract】Aiming to inadequate studies on multistage reinforced soil-retaining wall, the earthquake performance of two-stage geogrid reinforced soil-retaining wall was investigated by large-scale shaking table tests. The geometric similarity ratios of two-stage geogrid reinforced soil-retaining wall were deduced by Bockingham π theorem. The standard soil was taken as the backfill. The concrete blocks were selected as retaining walls, and the geogrid were regarded as the test model of reinforcements. The characteristics of the wall and the backfill were measured, and earth pressure, displacements of the wall and accelerations of the soil were obtained. The results showed that, soil-retaining wall under the action of the earthquake was slanted with the deformation pattern of the buckling and outward bulge. The lateral displacement, the settlements of the top and layered settlements increased with the rise in earthquake peak accelerations. The acceleration of the top of the retaining wall reached the maximum. With the increase in the input earthquake load, sand floew out from the crevice of the bricks. Subsequently, the top model brick fell down, and the retaining wall was destroyed. The acceleration had amplification effect along the wall height, and the amplification factor of earthquake peak accelerations decreased with the increase in peak acceleration motion. For the lower retaining wall, the distribution of horizontal peak dynamic earth pressure along the height was with a large value at the middle and a small value at both ends. For the upper stage retaining wall, with the small ground motion input, the distribution of horizontal peak dynamic earth pressure along the height was with a large value at the middle and a small value at both ends. With the large ground motion input, the distribution of horizontal peak dynamic earth pressure along height was with a small value at the middle and a large value at both ends. The horizontal peak dynamic earth pressure and horizontal displacement at the top of the lower retaining wall were larger than those at the bottom of the upper retaining wall. The result provided theoretical support for the seismic design of two-stage geogrid reinforced soil retaining wall.
【Keywords】 road engineering; reinforced soil-retaining wall; shaking table test; dynamic characteristic; seismic load;
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