DEBRIS FORCES ON HIGHWAY BRIDGES

This report contains the findings of a study undertaken to develop practical methods for determining drag and hydrostatic forces on bridge piers and on superstructures due to waterborne debris. The report includes recommended specifications for assessing these forces. The material in this report will be of immediate interest to bridge designers. The report is organized into four chapters and an appendix. The first chapter provides background information and discusses the objectives, tasks, and scope of the study. The second chapter summarizes the state of knowledge on the effect of debris on bridges. The chapter also discusses experimental studies conducted to determine a method for predicting debris forces on piers and on superstructures. The third chapter both introduces the recommended specification and commentary on debris forces and applies the debris-loading specification to three examples. The final chapter draws conclusions from the research and recommends areas for further research. The appendix provides a more detailed account of the procedures and outcomes of this research project.