Design of a Performance Monitoring System for an Innovative Geotechnical Slope Stabilization Design-Build Project

In June 2012, over 10 inches of rain fell within 24 hours in northeastern Minnesota, causing massive slope failures along a section of scenic Highway 210 through Jay Cooke State Park. The damage was so extensive that officials considered permanently closing the highway. However, local residents indicated their strong desire to re-open the highway and restore it to its natural appearance. The Minnesota Department of Transportation (MnDOT) solicited bids for a $21.3-million fixed-cost, variable-scope, design-build reconstruction project with three primary requirements: innovative slope-stability design methods that blended with the area’s natural setting, a three-year warranty on the repairs, and an extensive slope monitoring system to evaluate performance. The unique contract required stabilizing 74 slopes using innovative techniques along three miles of the steep terrain. Performance monitoring was of particular importance and advanced the limits of slope-monitoring instrumentation and communication in this remote project location through the use of 927 sensors and almost 2,700 monitoring points generating more than 20 million automated readings to date. This paper focuses on the development of the performance monitoring program through the design, installation and commissioning, construction, and three-year warranty periods.