Much of the historic road over the Cumberland Gap in the tristate area of Tennessee, Virginia, and Kentucky follows the original wagon road blazed in 1775. As the population of the region grew, the demand for road improvements became a constant. By 1973, relocation of the road was authorized through a tunnel, with the connection to U.S. 25E through the new tunnel requiring a cloverleaf with ramp to U.S. 58. Construction of the ramp began in 1990. Planned excavation was to cut as deep as 80 feet into Poor Valley Ridge (Tennessee), creating a significant potential for landslides. This article describes how the Federal Highway Administration's Eastern Federal Lands Highway Division designed a solution for this slope failure condition by reviewing data from past landslides and obtaining supplemental subsurface data.
Samenvatting