Slide Repair
Scotia Hollow Road
Allegheny County, PA
As part of the Allegheny County (Pennsylvania) Maintenance Department's Lateral Roadway Support Program, Earth, Inc. provided geotechnical engineering services for the evaluation and repair of various landslides, rockfalls, and retaining wall failures involving County roads. For the Scotia Hollow Road landslide project, Earth, Inc. performed a study evaluating numerous site grading, drainage, and structural schemes to control an uphill landslide condition approximately 200 feet in width extending approximately 400 feet uphill before settling upon the development of a cantilevered, soldier beam and lagging fall zone for landslide mitigation
Emergency Remediation Plan, Mon-Fayette Expressway, Section 52D, MP 40.6 NB
Landslide at Widened Fill No. 2
Carroll Township, Washington County, Pennsylvania Turnpike
A landslide occurred on a steep hillside at Widened Fill No. 2 along the S.R. 0043 (Mon-Fayette Expressway) varying in width from approximately 300 to 400 feet and comprising roughly 250 vertical feet from top to bottom. It included roughly 100,000 cubic yards of earth including fill comprised of excess excavated material from the construction of the adjacent Section 52D of the Expressway along with underlying original natural ground atop the west valley wall of Taylors Run. This slide movement resulted in debris flow over the valley wall towards Taylors Run whose relocation was key in the development of the successfully-implemented hillside stablization project.
Emergency Slide Repair, S.R. 0130 East of Trafford
Westmoreland County, PennDOT District 12-0
Remedial work was performed to evaluate and provide stabilization options along with design requirements for the remediation of a slide condition along S.R. 0130, a roadway with an ADT of 10,000 vehicles. Previous attempts to stabilize the initial slide were unsuccessful and the slide condition worsened, resulting in closing of the road and the corresponding need to develop a slide repair scheme that could be performed on an emergency basis. Recommendations were given for using select rock to construct a rock buttress embankment with a 2:1 slope to stabilize the roadway. Select (R-4 to R-7 sized) rock was recommended – instead of common earth – as such material could be readily placed in short segments in a manner that would not jeopardize the overall stability of the entire hillside. The use of select material also allowed for construction to proceed in cold, wet weather in a relatively short period of time, thereby hastening re-opening of the closed roadway.
