SOIL CREEP RATES UNDER PORTIONS OF THE HARTWICK COLLEGE CAMPUS: ONEONTA, NEW YORK

Soil creep can cause severe damage to structures built on the moving material. This motion is assisted by the presence of water. Water lowers the cohesion of the soil/ sediment and adds significant mass to the hillside. This study examines /monitors downslope movements on the Hartwick College Campus. Hartwick College is located in the northern Catskill Mountains of New York State. The campus occupies a portion of Oyaran Hill, with over 137 m (450 feet) of vertical relief. This paper focuses on the section of the hill that supports the Hartwick Tennis Courts. This section shows abundant evidence of soil creep including tilted trees, crack formation/ active propagation on the court surface and around the fence posts, sink-holes, collapsed retaining walls, uneven fence posts, and warped staircases. To analyze this downslope motion, crack propagation gauges, strain gauges, soil texture analyses, and ground penetration radar was used. These methods determined that the courts are collapsing and moving very quickly (up to 12 mm/year). This is primarily due to the unsorted, sandy loam/ loamy sand fill, used to grade the hillside, with a poor permeability allowing for water to accumulate and add weight. GPR imaging shows multiple planar scarps all dipping in the downslope direction. GPR imaging also showed the absence of drainage pipes beneath the courts. The extent of the damage to the courts, coupled with the poor design of the subsurface, suggests that moving the Hartwick Tennis Courts to a different location on campus might be the most cost effective solution.