An Analytical Evaluation of Passive-Resistance Performance of Highway Bridge Abutment Walls Using Incrementally Mobilized Shear Stresses

Abutment walls are integral components of bridge superstructures and play an important role in resisting lateral forces due to static and dynamic loading. Empirical methods for calculating lateral passive earth pressures are desirable computational tools in the design of bridge abutment systems. This thesis examines the development of lateral pressures behind a simple, vertical bridge abutment by analyzing the development of engineering strains in the fill material upon lateral loading. Laboratory testing, such as triaxial shear strength testing was conducted and/or evaluated on fill soils implemented in three unique load tests published in literature. The stress-strain curves from these tests were analyzed with respect to normal stresses and shear strains, and used to develop a mobilized shear strength profile for each representative soil type. Using log-spiral passive wedge failure modeling as proposed by Terzaghi combined with recent lateral displacement models found in literature, peak passive resistance was predicted within 17% of the experimental results with all case studies, with the load-deflection curve shape in general agreement with the measured curve for both strong and brittle wall failures