2012 Volume 27 Pages 141-148
To alleviate several serious problems with conventional type bridges, geosynthetic-reinforced soil (GRS) integral bridges for new construction and nail-reinforced soil (NRS) integrated bridges to reinforce existing conventional type bridges have been proposed. Model tests showed that the backfill settlement and destabilization by cyclic lateral displacements due to thermal expansion and contraction of the girder integrated to the abutments is restrained by reinforcing the backfill with reinforcement connected to the abutment. The seismic stability of these two new bridge types is very high due to increases in: 1) the initial stiffness; 2) the stiffness maintained during dynamic loading; 3)the damping ratio; and 4) the ultimate dynamic strength against response acceleration. By factors 1) and 2), the approaching speed to the resonance state becomes slower. By factor 3), the response acceleration becomes lower.
