Expander Body (EB) tieback anchors were installed in talus material in Glenwood Canyon and evaluated as to their ease of installation and performance. The EB consists of a steel tube with thin, folded walls which is expanded in the soil by injection of cement grout. The EB system can be expanded in coarse, angular materials at high pressure without rupturing. It, therefore, can be successfully used to limit grout take in permeable materials.
Based on the results of this study, the EB system was approved as a permanent anchoring method in construction of I 70 through Glenwood Canyon.
United States Department of Transportation, Federal Highway Administration, "Expandable Membrane Ground Anchors in Talus" (1989). Dams. Paper 2.