Rich Pohana, Geotechnical Engineer, City of Cincinnati - Columbia Parkway Landslide Stabilization

Presented By

Rich Pohana is the Geotechnical Engineer for the City of Cincinnati. He works in the Engineering Division of the Department of Transportation and Engineering. His main responsibility is to provide geotechnical expertise for landslide prevention and stabilization on city-controlled property. Rich also oversees the inspection, maintenance, and replacement of over 50 miles of city owned retaining walls. 

Rich obtained his B.S. in Geology in 1981 from Cleveland State University and his M.S. degree in Geology from U.C. in 1983. He began his professional career with the H.C. Nutting Company, a local Cincinnati geotechnical consulting firm. In 1989, he became the first and only engineering geologist employed by the City of Cincinnati. While working, Rich attended U.C.’s College of Engineering and Environmental Science and obtained a M.S. degree, specializing in geotechnical engineering in 1990. He obtained his Professional Engineer’s license in 2001. Rich was an Adjunct Professor in the College of Applied Science from 2004 to 2012, where he was the instructor for the Soil Mechanics course. 

Columbia Parkway Landslide Stabilization
Seasonal hillside instability has been a recurring problem along Columbia Parkway for decades in the form of abrupt landslides and gradual downslope movement of the colluvial overburden soils. Heavy rains saturate the overburden soils resulting in landslides and mudslides that overtop the existing wall and cascade onto the roadway, blocking lanes and disrupting traffic. Following a series of significant landslides in multiple locations along the uphill side of the parkway, the City of Cincinnati in 2019 sought a long-term stabilization plan and selected the design-build team of Beaver Excavating Co. as the primary contractor and Geotechnology, Inc. as its geotechnical design consultant to address 9 landslide sites along a two-mile stretch of the parkway. Two types of stabilization mechanisms for the project were implemented after evaluating the geologic conditions of the areas: soldier pile and lagging (SPL) walls, and soil nails with high strength steel mesh. The selection of the stabilization mechanism was based on the geometry of the ground surface and the subsurface conditions. The presentation will discuss the complexities of the landslides and the subsurface exploration program, as well as the design and construction of the stabilizations.

LOCATION: HALL OF MIRRORS

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