During the construction of New State Route 48 near Lawrenceburg, Indiana, the Indiana Department of Transportation encountered a zone of very weak ice-age lacustrine clay deposits. Excavations at the toe of these unstable slopes caused a series of shallow slides that rippled up to the crest of the hill, encroaching on INDOT’s right of way and causing safety concerns. GeoStabilization engineers designed a mechanical buttress at the toe of the slope that, in conjunction with minor filling behind the buttress, prevented further regression of these “infinite slope” failures. We kept total repair costs to a minimum by aggressively stabilizing the toe of the slide rather than attempting to treat the entire area. After many years of service, the buttress has prevented any further failures of the slope.
A state Department of Transportation in the Northeast had been monitoring a failing fill slope along a rural road that served as the only access for a group of residents (and a large sod farm) since 2000.