University of California, San Diego. Dept. of Structural Engineering
Abstract
65A0556This report presents results from shaking table tests on half-scale mechanically-stabilized earth (MSE) bridge abutments. The testing program consists of five tests where the direction of shaking is in the longitudinal direction of the bridge beam, and one test where the direction of shaking is perpendicular to the bridge beam. The longitudinal shaking tests include a baseline configuration and a parametric study of different configurations to investigate the effects of bridge surcharge stress, reinforcement spacing, reinforcement stiffness, and steel reinforcement on the seismic response of MSE bridge abutments. Experimental design of the scale model followed established similitude relationships for shaking table testing in a 1g gravitational field, including scaling for of geometry, reinforcement stiffness, backfill soil modulus, bridge surcharge stress, and characteristics of the earthquake motions. Facing displacements, bridge seat settlements, accelerations, vertical and lateral stresses, reinforcement strains, and contact forces between the bridge beam and bridge seat were measured for different instrumented sections to evaluate the three-dimensional dynamic response during a series of applied shaking motions. Results indicate that reinforcement spacing and reinforcement stiffness have the most significant effects on the facing displacements and bridge seat settlements for dynamic loading conditions
