Response-Spectrum Analysis for Barge Impacts on Bridge Structures

Abstract

Bridge structures that span navigable waterways are inherently at risk for barge collision incidents and therefore must be designed for impact loading. Current U.S. barge impact analysis procedures consist primarily of static load analysis methods that do not explicitly account for dynamic effects in barge–bridge collisions, and thus are not ideally suited to designing bridge structures to resist barge impacts. Therefore, the development of dynamic-analysis methods for estimating the responses of bridge structures to barge collisions is warranted. Dynamic-analysis procedures that use numerical time-integration techniques are capable of capturing pertinent dynamic effects but often yield voluminous amounts of time-varying results that must be post processed for use in design. In contrast, response-spectrum analysis (RSA) procedures are capable of directly producing maximum response parameters that are most pertinent to structural design. In this paper, an RSA procedure is proposed for use in barge impact analysis of bridges. The efficacy of the procedure is demonstrated for a bridge pier that was included in a series of full-scale impact experiments. The results obtained using the procedure are shown to be conservative when compared with data derived from the full-scale experiments.