16-Year Performance Update: Geosynthetic Reinforced Soil Walls as Integral Bridge Abutment Walls: Fid-Bau Portal

16-Year Performance Update: Geosynthetic Reinforced Soil Walls as Integral Bridge Abutment Walls

Simac, Michael R. / Elton, David J.

The first use of geosynthetic reinforced soil walls for integral bridge abutment construction in North America occurred on the Greenville Southern Connector (I-185) toll road in 1999. A second bridge with a longer span and higher loads was constructed in 2000 for the same project. Each of these four bridge abutment walls were constructed over 20 ft. (6 m) high using modular concrete block wall (MCBW) facing units and geosynthetic reinforcement with a silty fine to medium sand backfill around vertically driven steel H-pile foundation elements. While the piles were designed to carry all the vertical live and dead bridge loads, the lateral loads due to momentum, braking, and thermal movement would be transferred through the integrally cast-in-place concrete abutment to the piles laterally loading the wall facing elements, located just 3 ft. (1 m) behind the MCBW facing being restrained by the geosynthetic reinforcement within the abutment wall. This paper is a 16-year update on the service life performance of these MSE integral abutment walls based on visual observations and deformed shape measurement of the wall facing blocks. Results of survey monitoring of the wall facing deformations are presented and discussed. The wall face performance indirectly evaluates the distribution of stresses into the wall system structural components. This evaluation is done within the context of the prevailing 1998 FHWA (ASD) engineering analysis and design procedures for MSE walls utilized in 1999, including distribution of the pile induced lateral loads. A brief description of the geosynthetic installation details around the piles is presented to understand the applied analytical methods.