Item: Proposed avalanche control alternatives stanley avalanche, berthoud pass, colorado
Title: Proposed avalanche control alternatives stanley avalanche, berthoud pass, colorado
Proceedings: Proceedings of the 1992 International Snow Science Workshop, Breckenridge, Colorado, USA
Authors: Horst Ueblacleer, P.E.
Abstract: This paper covers a study to compare the feasibility of constructing avalanche sheds and other methods to control the Stanley avalanche on Berthoud Pass. The study consists of . preliminary field investigations, preliminary avalanche dynamics analysis, development of conceptual designs for avalanche sheds based on a recommended improved four-lane highway, and preliminary construction cost estimates for avalanche control alternatives. U.S. Highway 40 over Berthoud Pass is exposed to avalanche hazards at other locations, however, encounters with motorists at the Stanley slide paths are particularly dangerous because vehicles can be pushed over the edge of the roadway embankment and down steep slopes. The Stanley avalanche can be classified as medium-frequent and is expected to run after each medium to large snowstorm. Most avalanches block only the upper highway. The larger ones have been known to overrun the lower highway and come to rest at the foot of the opposite slope. Present avalanche control is by artillery fire or explosives dropped from a helicopter. Both methods are unreliable and involve high risks. They cannot be implemented when bad weather or poor visibility prohibit the use of artillery and flying, or when bake country skiers are in the area. The control alternatives proposed by this study consist of the non-structural GAZEX system and three types of structures: avalanche sheds, supporting structures (snowbridges and snow nets), and drift control structures. These may all be used either independently or in combination with each other.
Keywords: control, explosives, backcountry skiers, avalanche paths
Digital Abstract Not Available