Influence of pier stiffness on the response of bridge abutments to seismic loading: a simplified model

Past experience shows that bridge abutments attract a large portion of seismic forces during seismic events. It is often reported, in post earthquake investigations, the pervasive problem of insufficient shear capacity of the bridge transverse keys (i.e. Kocaeli, Turkey, Earthquake, Reconnaissance Report, Earthquake Spectra). The problem is, at the same time, related to the correct definition of design forces as well as to the design of details. However, an accurate determination of design forces, at shear key locations, is often difficult and requires the use of dynamic nonlinear analysis. The proposed solution provides a reasonable estimate of the maximum shear forces transferred to the abutments, simply based on pier strength, superstructure mass and maximum expected acceleration.