Dynamic response of bridge piers to ice forces

Abstract

An analysis of the dynamic response of bridge piers to measured ice loads is presented. The dynamic structural properties of piers and piles are described and the idealization of these structures for purposes of analysis is discussed. The characteristics of ice force histories recorded at a bridge pier in a large river in central Alberta are illustrated and the dynamic response of bridge piers to typical ice force events is determined. The results of this analysis are presented in the form of response spectra, which enable a rapid appraisal of the magnification, or reduction, in response that can result from dynamic effects. The analysis confirms that bridge piers, including massive ones, will fully respond to peak ice forces. Furthermore it shows that, depending on the natural frequency and damping of the pier and foundation, the dynamic response can exceed the static response to the peak ice force.