The seismic behavior of spill-through bridge abutments is investigated under static load scenarios. This paper focuses on the performance of spill-through bridge abutments and aims at providing a framework for their seismic analysis and design. To do this, an extensive parametric study is conducted utilizing the FLAC[1] finite difference analysis tool. The examined parameters include cohesionless soils with variable strength; two different pile configurations; and three different types of soil slope profiles. Effects of these parameters on important system outputs are evaluated. The investigated system outputs cover pile axial forces and bending moments, depth of point of zero shear below ground surface, pile top displacement, and shear stresses in the surrounding soil. It is shown that the strength and deformation response of piles under earthquake loads are significantly affected by actual soil slope profile. Thus, this study encourages dommittees of design codes to modify their design methods of spill-through bridge abutment to include the support effects of soil.

Pile group, Soil slope, Pile-slope system, Seismic behavior, Pseudo-static loads, FLAC