pacific nw transportation consortium region 10 Pactrans

A RAI of Data: Generalizing the Data-driven Rockfall Activity Index (RAI) based on Long-term Observations of Well Characterized Slopes

PI: Margaret Darrow (UAF), margaret.darrow@alaska.edu, ORCID: 0000-0003-4078-4746

Co PIs: Ben Leshchinsky (OSU), Michael Olsen (OSU), Joseph Wartman (UW)

AMOUNT & MATCH: $180,000 from PacTrans; $180,000 Match

PERFORMANCE PERIOD: 3/16/2022 – 3/15/2023

STATUS: Completed

CATEGORIES: Rockslopes, Geotechnical

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DESCRIPTION: The ultimate purpose of this new research is to improve and refine both the accuracy, and interpretation of the RAI analysis to promote its wider adoption by transportation authorities and consulting engineers in the PNW and across the nation. We believe that accomplishing this goal will place the RAI amongst PacTrans’ highest impact applied research products.

Based on numerous discussions and consultations with practitioners over the past two years (including several members of TRB’s rockfall subcommittee), we believe that improving the accuracy of hotspot mapping will lead to more widespread adoption of the RAI by practitioners in the PNW and other parts of the country. Accordingly, in this project, we propose improving the hotspot forecasting by developing a systematic procedure for selecting activity rates that directly account for local geology (e.g., rock type, tectonic setting), rock conditions (e.g., weathering grade), and climate conditions. Not only will this significantly improve the accuracy of the RAI forecasting, but it will also make the system generalizable to a more comprehensive range of rock slope settings in the U.S. and abroad.

To accomplish these goals, we will develop a new procedure to estimate the RAI activity rate based on in situ rock strength testing with a Schmidt Hammer and assessing yearly weather conditions. We will develop our activity rate assessment procedure using data from a series of approximately 20 thoroughly characterized test sites across a range of geologic and climate settings in Alaska and Oregon. The team previously developed high-resolution, multi-year change detection data for each of these sites, which are among the best-documented rock slopes in the United States.