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SR20 FALL CREEK
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Projects - SR 20 Falls Creek
Project Name: SR 20 Falls Creek Vicinity Unstable Slope
Location: Newhalem, WA
Owner: WSDOT
Schedule: July 6, 2004 through November 2005

Project Scope:
Dangling from a harness, 260 feet above Highway 20, a rock-scaler finishes securing another rock bolt drilled 20 feet into the mountainside.

Wilder’s mission on this stretch of highway is to remove and secure unstable material above the road that could slide onto hwy 20 without warning. After climbing, drilling, and blasting off a portion of the mountain, our scaler’s precarious job is to bolt the mountain itself back together with steel and epoxy resin.

In the fall of 2003, a thundering rockslide crashed into Highway 20 - blocking the roadway for nearly a month. Shortly after, Wilder was awarded the contract to excavate an embayment that will catch boulders and loose material from the rock slide area that rises nearly 1,000 vertical feet over the highway. This giant ditch will be 700 feet long, extend 100 feet into the uphill slope and have a depth of up to 300 feet from the existing slope to the embayment floor.
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Project Challenges:
Pioneering the access to the top of the cut area has been a rewarding, yet formidable challenge. Through the geotechnical data used to evaluate the project design, Wilder learned that the solid rock needed as a platform to stage necessary equipment was nearly 300 vertical feet above SR 20. This meant cutting a road into a nearly vertical slope over consistent highway traffic. As usual, Wilder rose to the occasion, building a road and cutting a bench at the top to stage the drilling and excavating equipment.

Another significant challenge is traffic. The embayment site sits between 1000 vertical feet of rock and the Skagit River Gorge – with SR 20 running through the center. Wilder crews work 6 days a week, 12 hours a day to complete this important public safety project. All of the excavated rock must be hauled off-site in highway trucks, and each time part of the mountainside is blasted away, the traffic must be stopped. This involves time-consuming, careful attention to traffic management.

With temperatures ranging from freezing in the fall, with plenty of rain, to over 100 degrees in the summer, the weather also factors in as a challenge. As with all the challenges, Wilder continues to complete the project on time and on budget.
 
 
 
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Wilder Construction is a wholly owned subsidiary of Granite Northwest Inc. | Site design and management by Blue Sky Projects