ABSTRACT
Roads are permitted to go through some deformation caused by a severe seismic event (so-called Level 2 such as 1996 Kobe and 2011 Tohoku) as long as they could be recovered quickly and easily. The authors have conducted to verify the effect of the countermeasure using geosynthetics sandwiched with gravel layers after a Level 2 seismic event through experiments and dynamic analyses. This countermeasure was found to be effective for maintaining the overall original shape of the embankment by suppressing the stretching of the toe of the embankment. It is legitimate for approach embankments near bridges and box culverts to be designed for a Level 2 seismic event. But because roads are extensive in the longitudinal direction, applying the Level 2 design for the rest of the embankment seems costly, thus Level 1 design approach seems feasible for these locations. Authors have verified the amount of settlement after a Level 1 seismic event (180 gal) by numerical simulations. The authors were able to summarize the settlement levels under various conditions that can be used as reference guidelines for designing embankments.
