Landscape Architect Articles

Highway Wall Falls12-30-05 | News

Highway Wall Falls

Warm weather that led to increased moisture in the soils could have been part of the mix that caused this retaining wall to slip, although the wall had a drainage system built into it.

The Utah Department of Transportation is trying to figure out how a 4,000-square-foot section of concrete retaining wall slid away from a stretch of highway under construction through Provo Canyon. Road crews discovered the separated wall, UDOT geotechnical engineers have examined it and UDOT will bring in the design and contracting firm that built the wall for a look. The wall slipped at a point about a half-mile down the canyon from the Deer Creek Dam.

There is no danger to motorists on the existing U.S. Highway 189, nor will the collapse lead to road closures. The 50-foot-by-40-foot section of wall was supposed to stabilize the walls near the dam. It is possible UDOT engineers overlooked or didn’t know about a problem with the soils under the wall, or the design may have been faulty. The contractor excavated the site in late spring and finished the wall in late November. The highway overhaul is a cooperative effort of UDOT and the U.S. Bureau of Reclamation, which governs the dam. Federal crews have been replacing unstable soils from the dam’s downstream base as part of a seismic upgrade.

Source: The Salt Lake Tribune.