Abstract: Field test was conducted to examine the structural performance of a mixed geosynthetics reinforced soil (GRS) abutment in the Mingguang to Chaohu Expressway project in Anhui Province. The horizontal stresses behind face slab and pile, horizontal dislacement and settlement of the face slab, and the geogrid strains were examined based on monitoring data collected over 330 days post-construction of the mixed GRS abutment. The impact of geogrid truncation on horizontal stresses was also examined. Results indicated that horizontal stress distribution behind the face slab was non-linear, with maximum values occurring in the middle, while stresses gradually increased towards the bottom due to toe restraint. Geogrid truncation around piles had minimal influence on horizontal stresses. Horizontal stress distribution behind pile was linear along the elevation, with reduced stress on the top due to the presence of cap beam. Furthermore, face slab deformations stabilized within 150-180 days post-construction, with maximum deformations observed near the road’s centerline. Geogrid strain distributed non-linearly along the wall height, demonstrating elastic behavior with shrinkage and rebound under service conditions, indicating the geogrid is far from reaching ultimate strain. Overall, the mixed GRS abutment exhibits minimal deformation, and the monitoring data collected during the service period can inform the design and construction of similar projects.

Key words: geosynthetics, reinforced soil abutment, geogrid truncation, filed monitoring, structural performance