Avalanche Characteristics and Structure Response: East Riverside Avalanche Shed, Highway 550, Ouray, Colorado

Details

• Creators:
  Mears, Art
• Corporate Creators:
  Art Mear Consulting
• Corporate Contributors:
  Colorado. Department of Transportation ; United States. Department of Transportation. Federal Highway Administration
• Subject/TRT Terms:
  • Avalanches
  • Data collection
  • Equations
  • Fatalities
  • Load cells
  • Loads
  • Mathematical models
  • Measurement
  • Mechanical strain
  • Momentum
  More +
• Publication/ Report Number:
  CDOT-DTD-R-92-4
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Colorado
• Edition:
  Final Report
• Corporate Publisher:
  Colorado. Department of Transportation
• Description:
  The East Riverside avalanche path crosses Highway 550 approximately 5 miles (8 km) south of Ouray, Colorado. By itself, the East Riverside represents approximately 10% of the total avalanche hazard between Ouray and Durango and has caused five fatalities in three separate accidents in 1963, 1970, and 1978. In 1985, the Colorado Department of Highways built a 180-foot (55 m) long avalanche shed to protect the highway from the smaller, frequent avalanches. During construction, 32 strain gages and six load cells were welded to reinforcing steel in the structure to measure avalanche-induced strains and loads. These data are intended to be used for future shed design. Avalanche velocities were measured in two events and estimated in eight others by a simple empirical runup equation. Measured and computed velocities ranged from 69 to 124 mph (31 to 55 m/s); however, avalanches were relatively small, ranging from 10 to 30% of design size. More detailed avalanche-dynamics calculations applied a stochastic particle model to compute velocity and momentum distributions at the shed and compute shear stresses. The results of the runup equation and stochastic modeling were in general agreement with measurements. The central core of flowing avalanche debris was confined by the shed in 11 of 12 events; however, the powder blast extended beyond the north portal in six avalanches, and beyond both portals in four avalanches. Any future shed extension should first be built on the north end.
• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/93949/dot_93949_DS1.pdf
• File Type:
  [PDF - 6.92 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:47ed55043326b5c632a9061c9d06de73d483b34cfc065a86087f9b3feaa427d8b51870008077e23fb1641ddc3302b66b8edf7de71f4e2ff16f596db5b612665d