Behavior of Geocell-Reinforced Soil Abutment Wall: A Physical Modeling

The use of geosynthetic-reinforced soil (GRS) structures instead of pile foundation in bridge abutment walls leads to reduction in costs and bridge bump. This study evaluates the effect of geocell as reinforcement on the bearing capacity of the backfill soil, the footing settlement, and the horizontal displacement of the wall facing of the GRS abutment wall. For this purpose, through physical modeling of the abutment wall and strip footing on backfill soil, a series of tests was carried out with changes in the value of the parameters such as the diameter of an equivalent circular area of the geocell pocket opening, the number of geocell layers, and the distance of backfill soil surface to the first layer of geocell. The output of the experiments showed that the increase in the diameter of an equivalent circular area of the geocell pocket opening results in greater horizontal displacement of the wall facing and reduction in bearing capacity of GRS abutment wall. Also, the best performance of the geocell-reinforced soil wall can be seen when the distance of the backfill soil surface to the first layer of geocell was 0.1 times the footing width. Increase in the numbers of geocell layers leads to increase in the bearing capacity of footing and the optimal number of geocell layers as reinforcement depended on the amount of pressure applied to the abutment wall. The results show that the optimum number of geocell layers as reinforcement for the footing pressures of 156, 188, and 205 kPa were four, five, and six, respectively. Also, the results showed that the abutment wall facing was deformed in the form of bulging and the rotation outward.