MITIGATING OHIO LANDSLIDES WITH LAUNCHED SOIL NAILS

This paper presents the use of Launched Soil Nails to mitigate shallow landslides in Ohio. Case histories and design considerations, applicable to Ohio geology will be discussed.

Ohio has five recognized landslide-prone areas. These are the: Lake Erie Shoreline; Cuyahoga River Valley, Lake Deposits; the Upper Allegheny and Lower Permian red-bed strata; the Scioto River Valley, Bedford shale deposits, and the Ordovician Kope Formation. Landsliding occurs throughout the state, but these five regions are proliferated with ancient and active landslides. The financial impact of Ohio landslides in recent years exceeded $10 million per year.

Many factors affect slope stability in the State including: land use and development, stormwater management practices, inherently weak soils, and Early and Middle Stage stream topography. The above-normal precipitation in 2003 and 2004 triggered hundreds of landslides throughout Ohio. Slides resulted in road closures; damage to property and infrastructure; and an unexpected financial burden to both the public agencies responsible for landslide mitigation and private residents needing to protect their homes and land.

The unexpected increase in landslide activity has public and private owners seeking an expedient and economical solution to stabilize landslides. Use of launched soil nails to stabilize shallow landslides has been evaluated by several Ohio County Engineers, ODOT Districts, engineering consultants, construction contractors, and private homeowners. The stabilization technique has been used in each in of Ohio's five landslide-prone areas.

This paper presents a brief case history from each of Ohio's landslide-prone areas, which will include slide magnitude, strata, groundwater conditions, and other contributing factors to the instability. General guidance on the evaluation and design methodologies of launched soil nails will be included.