Centrifuge model study on deformation behaviour of geocell retaining wall with loose backfill

Backfill relative density is one of the main variables determining the response of geosynthetic-reinforced walls. However, the deformation behaviour of a geocell retaining wall (GCRW) with a loose backfill has not been thoroughly explored in the literature. Therefore, a series of centrifuge tests was conducted at 30 g, and the horizontal facing displacement and top-surface vertical displacement of the models were compared. The main variables included geocell zone configuration, reinforcement inclusion and type (geogrid or geocell), geocell equivalent diameter, pin placement, and wet conditions. Results showed that a GCRW configuration with a width increasing from top to bottom reduced the maximum horizontal and vertical displacements by 54.4% and 46.8%, respectively, compared with a constant-width GCRW. However, reinforcing the constant-width GCRW was a more effective method in reducing the maximum horizontal displacement by 59.4% and 68.6% with geocell and geogrid, respectively. Geogrid-reinforced GCRW exhibited 5.9% reduction in maximum horizontal displacement either by decreasing the geocell equivalent diameter from 36 cm to 21 cm (in prototype dimensions) or by placing pins in the geocell zone. Wet conditions had a greater impact on the geogrid-reinforced GCRW, resulting in a 17.6% increase in maximum horizontal displacement, whereas the geocell-reinforced GCRW exhibited a 6.4% increase.