Rockfall Hazard Process Assessment: Project Summary

2017PDFTech ReportFHWA/MT-17-008/8239-001Asset managementCostsDatabasesDecision support systemsEvaluation and assessmentRatingsRisk assessmentRock slopesRockfallsUnited StatesMontana. Department of TransportationBeckstrand, Darren L.Black, Brent A.Mines, AineGeorge, BenjaminThompson, Paul D.Stanley, DavidLandslide TechnologyDA Stanley ConsultingMontana. Dept. of Transportation. Research ProgramsUS Transportation CollectionThe Montana Department of Transportation (MDT) implemented its Rockfall Hazard Rating System (RHRS) between 2003 and 2005, obtaining information on the state's rock slopes and their associated hazards. The RHRS data facilitated decision-making in an informal process over the next several years. MDT applied the RHRS ratings in an informal process, reviewing ratings and comparing them to event occurrences, maintenance needs, and rockfall mitigation project selection in the decade since completion. MDT found the RHRS to be a valuable tool providing relative rankings between sites. After nearly a decade of using RHRS, MDT decided to develop a more comprehensive and updated Rock Slope Asset Management Program (RAMP), beginning in 2015, due to a combination of changed sites, a need for additional tools to aid in project selection, and a desire to incorporate principles of Transportation Asset Management (TAM) in managing rock slopes. The goal of the new research project is to assess changes in MDT's rock slope assets since 2003 and gather data that would allow MDT to develop an updated rock slope hazard assessment program with TAM-compatibility as an added benefit. The research project scope includes identifying rock slope condition and risk factors, determining critical sites, incorporating benefit/cost analysis, and forecasting future asset condition based on various budget scenarios. The objectives of the program are to 1) update rock slope rating criteria; 2) determine critical sites based on condition, risk, and cost/benefits using new decision support tools; 3) develop/ cost benefit scenarios; and 4) evaluate compatibility of the RAMP process with MDT's Transportation Asset Management program. Landslide Technology of Portland, Oregon, with team members Paul Thompson, DA Stanley Consulting, and Geographic Communications Systems, completed the project in 2017.90