Kettle Falls Railway Ground Hazard Relative Risk Assessment

December 10, 2020

This paper presents the application of a semi-quantitative ground hazard relative risk assessment methodology applied for the Kettle Falls Railway, which represents 282 km of track in northeastern Washington State and southern British Columbia. The methodology consists of a proactive and structured system to manage the risk related to ground hazards, including rockfall, rockslides, debris flows, debris falls, earth flows, and river and hydraulic erosion hazards. The objective of the system is to optimize safety and reduce costs related to service disruptions and derailments. The system was used to identify, assess and rank the risk related to ground hazards at regional/corridor scale. In addition, it allowed comparison between the various types of ground hazards in a consistent manner. The results are presented in terms of relative risk scores used for prioritization of mitigation work along the railway alignment. An analysis of meteorological data associated to past incidents provided interesting results about ground hazard triggering mechanisms such as freeze-thaw cycles. Past incidents were observed to occur at different stages of freeze-thaw cycles allowing the definition of a freezing trend and a thawing trend. These observations are consistent with other studies published in the literature and may suggest a possibility to refine risk estimations at a seasonal level. Sturzenegger, M., T. Keegan and T. Simoes. 2016. “Kettle Falls Railway Ground Hazard Relative Risk Assessment,” in: GeoVancouver, History and Innovation, 69th Canadian Geotechnical Conference, Vancouver, British Columbia, October 2-5, 2016. Canadian Geotechnical Society.