Physical modelling of geosynthetic reinforced earth wall as a bridge abutment

Geosynthetic Reinforced Soil (GRS) walls could be used as appropriate substitutes for abutment of integrated bridges, for they not only offer financial advantages but also have an enormous impact on reducing asymmetric settlement between the deck and the surrounding soil. Since the bridges constitute a key element of the lifelines, investigating monotonic and cyclic behavior of these structures is of particular importance. To this aim, a series of physical models of the abutment were tested in order to investigate the behavior of bridge footings on GRS walls. In this study, the effect of footing distance from the wall facing on the stress and deformations of the wall has been investigated. The walls were constructed with a scale factor of 1 to 5. The wall elements were simulated using cubic concrete blocks of 50×50×45mm for facing, four geosynthetic layers as reinforcing elements, and Firoozkouh D11 sand as filling material. Monotonic loading was imposed on a strip footing with a width of 75 mm located at different distances from the facing. Results showed that the distance of footing from the wall facing strongly influence GRS failure mode. The failure mode was local failure of the wall facing for near face footing, whereas enormous footing settlement was controlling factor for the load bearing capacity of the far footing. Results indicated that, if the critical distance (2B) from the wall facing is observed and the bearing capacity of the footing is provided, a proper bridge performance could be expected.