Abstract
Large earthquakes often lead to large differential settlement between bridges and their approaches. In some of these cases, emergency vehicles cannot pass the unevenness after earthquakes. In order to mitigate this problem, confinedreinforced earth (CRE) method was introduced in subgrade layer, at the bottom of pavement layer of road structures. Some laboratory prototype scale model test with various prestress in geogrid layers were carried out to investigate the effects of prestress on deformation of confined-reinforced layer due to differential settlement. The levels of prestress is applied via prestrain set as 0%, 0.016%, 0.05% and 0.1% in elongation. The results show that the prestress in geogrid plays an important role in reduction of differential settlement between bridges and their approaches.