Vertical Motion of Highway Bridge Structures Due to an Earthquake

摘要

The dynamic response of continuous highway bridge superstructures due to pulsating support settlements induced by an earthquake is investigated. A governing differential equation for the dynamic behavior of bridge superstructures under pulsating support settlements has been formulated and a Fourier series type solution method is presented. The results have been successfully compared to those obtained by a dynamic three-moment equation. Four separate computer programs have been developed to facilitate the analysis and comparisons. The concept of dynamic amplification factors as the ratios of dynamic responses to static responses has been developed and subsequent charts have been plotted. Unusually high dynamic amplifications were observed, particularly in shearing forces. The reasons for such high values have been traced.