OasisLMS

Abstract:

Confidential Project - Earth Retention in the Rocky Mountains on a Moving Landslide 

Mary Ellen Large, P.E., BC.GE¹ and Nigel Miller²Â 

¹ Nicholson Construction Company, 2400 Ansys Dr., Ste. 300, Canonsburg, PA 15317; Email: maryellen.large@nicholsonconstruction.com; Phone: (412) 221-6608 

² Nicholson Construction Company, 5161 E Arapahoe Rd #420, Centennial, CO 80122, Email: nigel.miller@nicholsonconstruction.com; Phone: (385) 270-2863 

A new resort (confidential project) is being developed in the Rocky Mountains that includes residential lots, ski slopes and lifts, a golf course, and common utility, sewer, and roadway infrastructure.  The construction for this resort has extended over multiple phases.  The resort covers 12,740 acres and sprawls across mountain terrain up to an elevation of 9,570 ft.  The general contractor awarded the earth retaining systems work to Nicholson Construction Company (Nicholson) in 2022 for constructing the resort’s main access road and a large diameter storage tank. 

The main access road into the resort is called the East Access Road (EAR).  The road is 0.68-mile long and crosses rocky terrain with a sharp elevation difference between the mainline and the top of the ski area.  The road is flanked by ground that ranges from generally level to very steep requiring various earth retention systems.  Along the EAR alignment, Nicholson constructed three soil nail retaining walls with a reinforced mesh system and one tieback anchor wall with reinforced shotcrete facing.   

Nicholson was also contracted to design and install a semicircular permanent soil nail retaining wall for the construction of Tank 4, which is a 1-million-gallon, partially buried, cylindrical ground storage tank located at an elevation of 6,600 ft.  Nicholson drilled and installed close to 400 fully encapsulated solid thread soil nail bars for this tank.  Summit GeoStructures installed the permanent shotcrete comprising wire reinforcement, drain boards, and drain outlets.  Three sacrificial soil nail verification tests were performed, and 5% of the production soil nails were proof tested. 

The presentation will cover the scope of the work and project challenges, including access, equipment supply, soil and rock formations, and construction progress in inclement weather conditions.   The discussion will highlight the complexity of the design and installation of these projects particularly considering the entire site within a global moving landslide.