Allowable Bearing Pressures of Bridge Sills on GRS Abutments with Flexible Facing

• Published in: Journal of geotechnical and geoenvironmental engineering Vol. 132; no. 7; pp. 830 - 841
• Main Authors: Wu, Jonathan T. H, Lee, Kevin Z. Z, Pham, Thang
• Format: Journal Article
• Language: English
• Published: New York, NY American Society of Civil Engineers 01.07.2006
• Subjects: Applied sciences; Bridge elements; Bridges; Buildings. Public works; Earthwork. Foundations. Retaining walls; Exact sciences and technology; Geotechnics; Stabilization. Consolidation; TECHNICAL PAPERS; Geosynthetics; Geosynthetic material; Stress strain relation; Pressures; Bridge abutments; Pressure; Recommendation; Finite element method; Bridges; Settlement; Abutment; Analytical method; Loadbearing capacity; Retaining walls; Retaining wall; Reinforced soil; Comparative study
• ISSN: 1090-0241; 1943-5606
• DOI: 10.1061/(ASCE)1090-0241(2006)132:7(830)

Compared to geosynthetic-reinforced soil (GRS) retaining walls, GRS abutment walls are generally subjected to much greater intensity surface loads that are fairly close to the wall face. A major issue with the design of GRS abutments is the allowable bearing pressure of the bridge sill on the abutments. The allowable bearing pressure of a bridge sill over reinforced soil retaining walls has been limited to 200 kPa in the current NHI and Demo 82 design guidelines. A study was undertaken to investigate the allowable bearing pressures of bridge sills over GRS abutments with flexible facing. The study was conducted by the finite element method of analysis. The capability of the finite element computer code for analyzing the performance of GRS bridge abutments with modular block facing has been evaluated extensively prior to this study. A series of finite element analyses were carried out to examine the effect of sill type, sill width, soil stiffness/strength, reinforcement spacing, and foundation stiffness on the load-carrying capacity of GRS abutment sills. Based on the results of the analytical study, allowable bearing pressures of GRS abutments were determined based on two performance criteria: A limiting displacement criterion and a limiting shear strain criterion, as well as the writers’ experiences with GRS walls and abutments. In addition, a recommended design procedure for determining the allowable bearing pressure is provided.