Development of GIS-based decision support systems for stability analysis of slow moving, active landslides using geotechnical modeling

摘要

A GIS-based decision support system for the near-real-time analysis and interpretation of landslide monitoring data is being developed. The decision support platform will be based on realistic rule sets generated through the analysis of case histories of instrumented slope behaviour. In this paper, the case study of a slow moving, active landslide that has been continuously monitored for over 25 years is discussed. Within the lifetime of the slide, stabilization procedures in the form of drainage works have been undertaken, primarily 21 years ago, and as a result have lowered the rate of displacement from approximately 10mm/yr to less than 2 mm/yr (Imrie et al, 1991). Work in progress for this project has several inter-related components including: the incorporation of geotechnical data into a GIS database customized for geotechnical data presentation and visualization, and the acquisition of results from simulations conducted using a calibrated numerical model to assess factors influencing landslide movement processes. Data from various geotechnical instruments has been integrated into the GIS platform, along with information about the geometry and geology of the site. Numerical models have been used to understand the sensitivity of the slope stability to variable material properties and changing water table levels. From these analyses, preliminary rules for automated, ongoing assessment of the network of geotechnical instrumentation data will be proposed. These rules are expected to provide additional information for triggering warnings and alerts in the event of changing conditions, both in real time and from analysis of archived data.