LITERATURE REVIEW OF GEOSYNTHETIC REINFORCED SOIL-INTEGRATED BRIDGE SYSTEM

Geosynthetic Reinforced Soil-Integrated Bridge System(GRS-IBS) is a new technology proposed by the United States for the rapid replacement of single-span bridges with medium and small size. It is an optimization and enhancement of the original GRS abutment technology. So far, the GRS-IBS structures have been designed and constructed for more than 250 bridges in 44states in US and engineering experiences have been accumulated for more than 10 years. This paper performed a literature review of more than 40 GRS-IBS structures in the US. The performance of the GRS-IBS structures has been investigated from field monitoring data, vehicle loading tests, and numerical analysis. Research results showed that the differential settlement between the bridge slab and the approaching embankment was minimized in the GRS-IBS structures. The change of temperature had little effect on the performance of the structures. The lateral earth pressure behind the facing was low and uniformly distributed along the height, which was not consistent with Rankine lateral earth pressure theory. Small tensile force developed in the geosynthetic reinforcement. The failure surface behind the wall facing matched well with the active Rankine failure surface at the lower portion of the wall. At the top of the wall, the failure surface deviated from the active Rankine failure surface. In addition, parametric study using numerical analysis showed that proper compaction of backfill soil and small spacing between reinforcement material were two key factors to ensure good performance of the GRS-IBS structures after construction. The increase of the friction angle of the backfill soil resulted in the increase of the interface friction angle between the geosynthetic reinforcement and the backfill soil, hence the smaller settlement and lateral deformation.