Stabilization of the Bender's Park Landslide, Lead, South Dakota

摘要

Snowmelt and spring rain following an unusually heavy snowfall in the winter of 1993-1994 resulted in pronounced slope movement of the 350,000 m~3 Bender's Park landslide in Lead, South Dakota. This caused movement of the 21 homes located on the affected slope. A detailed study of the slide was initiated in 1994 when the slope movement also caused structural damage that forced the closure of a recently-constructed shopping mall at the toe of the slope. During the fall of 1995 stabilization efforts began by constructing deep, rock-filled trenches extending below the failure plane along the head and toe of the slide, for the dual purposes of providing increased shear resistance and to enhance subsurface drainage. Following construction, a continued overall decrease in the rate of landslide movement occurred over a period of about four years, and is attributed to the effectiveness of the trenches in providing increased stability as the slide movement developed passive resistance in the rockfill. The last sets of inclinometer readings taken in early 2002 showed no detectable movement.