Geosynthetic reinforcement of backfill behind integral abutments to mitigate approach slab distresses. (15th October 2022)

• Record Type: Journal Article
• Authors: Liu, Hao; Han, Jie; Parsons, Robert L.
• Is Part Of: Engineering structures. Volume 269(2022)
• Publication Date: 2022-10-15
• Subjects: Geosynthetic -- Integral bridge abutment -- Seasonal temperature change -- Traffic loading -- Approach slab -- Differential settlement; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2022.114772
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Differential settlement or bump at end of bridge is a common geotechnical and structural problems for integral bridge abutments. Approach slabs are commonly used to provide smooth transition between approach embankments and bridge abutments, but often experience distresses during service due to temperature changes and traffic loading. Geosynthetic reinforcement may be used to mitigate approach slab distresses. This study demonstrates the benefits of geosynthetic reinforcement in minimizing settlement of backfill and differential settlement of approach slabs. This study found geosynthetic reinforcement with wrap-around facing and extended length of top layers provided effective mitigation of approach slab distresses. Abstract: An approach slab typically has a negligible settlement on one end supported by an integral bridge abutment, but a considerable settlement on the other end underlain by a sleeper slab on the backfill due to factors including seasonal temperature changes and traffic loading. As a result, a differential settlement develops between the two ends of the approach slab, resulting in an abrupt change of the pavement gradient. Furthermore, the concave deformations of the approach slab under traffic loads exacerbate this abrupt gradient change, which creates a hazardous condition for vehicles. Four physical model tests were conducted to investigate the feasibility of using geogrids in the backfill to mitigate these approach slab problems due to simulated seasonal temperature changes and traffic loading. The test results showed that geogrids could significantly reduce the settlements of the backfill away from the abutment, which were mainly caused by traffic loading. Horizontal geogrids increased the backfill surface settlements near the abutment, while wrap-around geogrids significantly reduced these settlements. Longer top geogrid layers with wrap-around facing could further reduce the backfill surface settlements near the abutment.