Development of Guidelines for Incorporation of Vertical Ground Motion Effects in Seismic Design of Highway Bridges

摘要

This study was undertaken with the objective of assessing the current provisions in SDC-2006 for incorporating vertical effects of ground motions in seismic evaluation and design of ordinary highway bridges. A comprehensive series of simulations was carried out on a range of typical bridge configurations to isolate the effects of vertical motions. Results of these analyses reveal that vertical ground motions can have a significant effect on (i) the axial force demand in columns; (ii) moment demands at the face of the bent cap, and (iii) moment demands at the middle of the span. The first two issues are found to be less of a concern in the present study since the axial capacity of the columns and the moment capacity of the girders at the face of the bent cap are generally adequate to resist the increase in the respective demands due to vertical effects.