SR68 Midland Road Emergency Landslide Repair: Let’s Try Something Different-Video

Video Transcription

Video Summary

The presentation described emergency landslide remediation along SR-68 in Beaver County, Pennsylvania, beside Norfolk Southern’s rail corridor. Longstanding slope movement had repeatedly damaged the road and displaced railroad tracks; record rainfall in 2018 triggered a major failure and forced a lane closure. Historical borings, inclinometers, piezometers, and geophysical data helped identify an old landslide rather than mine subsidence. Monitoring showed movement increased as groundwater levels rose, supporting a design that addressed both slope stability and drainage.<br /><br />The selected solution installed deep soil-mixed columns through the embankment to bedrock, supplemented by drainage. The contractor proposed larger, seven-foot augers instead of the designed three-foot columns; the revised layout still met the required soil-replacement ratio while preserving drainage paths. Bench-scale tests, field trial panels, coring, strength tests, and uniformity checks established the mixing requirements. Key construction lessons included accounting for thick accumulated asphalt, confirming treatment elevations with reliable survey controls, and adapting installation depth to equipment limitations.

Keywords

landslide remediation

SR-68 Beaver County

slope stability

soil-mixed columns

drainage design

Norfolk Southern rail corridor