State Highway 82, Snowmass Canyon Project, Aspen, CO

Colorado Department of Transportation and Parson Transportation Group

The State Highway 82 Snowmass Canyon Project consisted of improving and widening five miles of highway from two lanes to four near Aspen, Colorado. Yeh and Associates role on the project was to provide geotechnical investigation and recommendations, landslide evaluation and mitigation design, retaining wall design, pavement design, construction inspection and materials testing services. Our firm prepared the design drawings and specifications for the retaining wall systems, foundation systems and landslide stabilization. A combination ground anchor and micropile foundation system was developed for the retaining structures resulting from our Value Engineering evaluation, saving construction time and cost. Yeh completed the design and construction documents and met the original design schedule.

Geologic hazards that were identified on the project included landslides, debris fans, rockfall, and difficult foundation conditions including collapsible soils. The competency of some of the bedrock in the area was affected by faulting. Environmental concerns were a major issue throughout the project due to its location in a pristine canyon environment. In addition, the terrain in the project area consisted of very steep slopes, some up to 65 degrees.

Yeh and Associates addressed issues relating to the design and construction of numerous permanent earth retaining structures and concrete box culverts. Yeh and Associates also evaluated the geotechnical aspects of the design and construction of six bridges on the project. Seismic hazards were also evaluated.

Yeh and Associates provided designs for the project including deep foundations (drill piers and micro-piles), ground anchors, soil nails, and MSE walls. The alignment was designed with both cut and fill retaining walls. Because of the steep terrain, retaining walls ranged to over 40 feet in total height and vertical cuts up to 25 feet were secured with ground nails or tiebacks. We developed a landslide instrumentation system. Inclinometers and piezometers were installed and monitored for earth movements and wall settlements. Yeh and Associates provided on-site construction inspectors, materials testers and field engineers for the construction project.

Yeh’s key personnel that worked on the project included Shan-Tai Yeh who was the principal in charge, Rick Andrew was the project manager, Roger Pihl was the project geologist and manager of the construction observation and Ben Arndt was the project engineer.