SPR 22-628, Current Practices in Rock Scaling

PROBLEM STATEMENT Rockfalls occur frequently along many Kentucky roadways and pose a risk to the traveling public. They result from the chemical and physical weathering of unmaintained aging exposed rock cuts. KYTC’s go-to practice for mitigating rockfalls often requires substantial excavation, procuring additional right of way, and/or hiring specialty contractors. A new approach is needed to maintain rock cut slopes and preserve motorist safety. Many DOTs have adopted rock scaling as a cost-effective rockfall mitigation tool. Rock scaling entails removing loose and unstable rocks from rock cut slopes within the right of way to reduce rockfall risk. It typically involves the use of hand-operated pry bars and picks to remove unstable material, but mechanical means can be incorporated if necessary. Slopes are usually accessed by a small team of qualified individuals on foot or using rope access, or by telescopic boom lifts and crane baskets. OBJECTIVES • Document current practices for rock slope scaling adjacent to highways • Investigate methods used by DOTs for contracting, estimating, in-house scaling, debris removal, and assessment of scaling locations • Recommend rock scaling practices that can be used at KYTC