Integrating Change Detection and Slope Assessment for Enhanced Rock Slope Asset Management

Alberta Transportation and Economic Corridors is currently working towards the development of a formalized geotechnical asset management program, which requires linking rockfall geohazard condition assessment tools with rock slope performance. Integrating the use of remote sensing technologies with condition assessment tools based on engineering geology concepts may provide transportation agencies with a methodological basis to aid in the prioritization of capital expenditure for rockfall geohazard sites. Presented in this paper is a methodology to develop a direct correlation between slope condition assessments and slope performance metrics derived from change detection. The methodology is demonstrated using an initial database of change detection results for three rockfall geohazard sites in Alberta, Canada where a suite of rock slope and rock mass rating systems were applied, including Alberta’s current condition assessment tool, the Geohazards Risk Management Program Risk Level rating. Rockfall metrics including annual failure volumes and annual frequencies for events greater than or equal to 1 m³ were derived from the change detection results and compared with the results of the rock slope and rock mass rating tools for each of the study sites. Strong correlations were achieved between each rating system and the rockfall metrics derived from the change detection results. This methodology provides a direct correlation between practical condition assessment tools and rock slope performance monitoring techniques to be used along transportation corridors to improve prioritization of maintenance and remediation based on a quantified level of hazard.