The nature of rockfall as the basis for a new fallout area design criteria for 0.25:1 slopes.

PDFTech ReportFHWA-OR-GT-95-05SPR 5287FalloutData collectionSlopesDesign chartsRockfallsData analysisOregonOregon. Department of Transportation. Geotechnical Services UnitPierson, Lawrence A.Davis, Steven A.Pfeiffer, Timothy J.Oregon. Department of Transportation. Geotechnical Services UnitUnited States. Federal Highway AdministrationOregon. Dept. of Transportation. Research UnitUS Transportation CollectionThe data gathered from rolling nearly 2800 rocks off several 0.25H:1V slopes into three differently shaped ditches (flat, 6H:1V and 4H:1V) was used to develop 12 design charts for rock fallout areas. The data were analyzed using simple statistical and graphical methods. The charts can be used to size fallout areas that satisfy specific rock catching requirements. Based on slope height and the shape of the ditch, the charts identify the required fallout area widths that will restrict set percentages of rockfall ranging from 10% to 100% in 10% increments along with 95% and 98%. This report documents the test method, the means of analysis, the research results, and sample applications of the results. The data results in both tabular and graphical form are included in the appendices