Geogrid-reinforced lime-treated cohesive soil retaining wall: Case study and implications

Lime-treated cohesive soils are used extensively as the construction materials of road embankments. In some cases, vertical embankment is needed, rendering the necessity to employ retaining walls backfilled with lime-treated cohesive soil. In China, geogrid-reinforced lime-treated cohesive soil retaining walls are increasingly used for this purpose. With the objective to reveal the behavior of this type of structure under working-stress condition and to shed light on its future application, a 6.0 m reinforced soil retaining wall was monitored for two years during and post construction. The results showed that the lime-treated soil carried the majority of the gravity load but the geogrid reinforcements also contributed to the integrity of the embankment. Under gravity loading, the backfill deformation was mainly elastic. Backfill compaction during construction was the critical factor influencing the reinforcement deformation and lateral earth pressure at the back of the facing, the latter of which decreased with time after the end of construction due to the increases of both backfill strength and facing displacement. Based on these results, it is inferred that under working stress condition, lime-treated backfill plays a major role in the stability of the retaining wall, while geogrid reinforcements play a secondary role.