Abstract
Geosynthetic-Reinforced Soil Integral Bridge (GRS-IB) consists of an integral bridge comprising a girder unified to a pair of abutment and the backfill reinforced with geosynthetic-reinforcement layers connected to the back of the facing. It is shown that, cement-mixing the backfill zone immediately behind the abutment, GRS-IB becomes more stable against seismic load as well as cyclic displacements at the top of the abutment due to seasonal thermal deformation of the girder. Failure of GRS-IB is triggered by passive failure at the top of backfill, which results into a pushing out of the bottom of the abutment. It is effective for an increase in the stability of GRS-IB against both seismic and static loading to increase the passive resistance by cement-mixing a relevant zone of the backfill. The above was validated by performing a series of shaking table tests and static cyclic lateral loading tests on scaled models of GRS-IB.