Soil Nail and MSE Wall for Stabilization of the Elbow Fill Slide, Snake River Canyon, Wyoming

摘要

Reconstruction of US Highway 26-89 through Snake River Canyon in Wyoming required stabilization of the Elbow Fill Slide and an effective means to support the overlying roadway. A request for design/build proposals resulted in construction of a soil nail wall at the Elbow site. This was the first soil nail wall project for the Wyoming DOT. In cooperation with the Federal Highway Administration, the wall was designated an "Experimental Feature" and an instrumentation and monitoring program was undertaken. Instrumentation includes slope inclinometers for measuring wall deformations and strain gauges attached to the soil nails for the purpose of evaluating mechanisms of load transfer from the ground to the structural components of the wall. Objectives of the study are to: (1) provide verification of wall performance, especially pertaining to control of landslide movements and resulting damage to the roadway, (2) evaluate field load transfer to the soil nails compared to the loads assumed for design purposes, and (3) evaluate the construction and cost viability of soil nailing as a slope stabilization system, for the purpose of utilizing soil nails in similar, future projects. This paper summarizes the site conditions, design aspects, and construction of the soil nail wall. Performance of the wall, based on field observations of ground movements and load transfer in soil nails, is described and discussed.