Construction of I-70 through Glenwood Canyon in Colorado has required several viaduct structures to be constructed on the talus slopes of the canyon. The talus has a high percentage of voids, and there is much concern that settlement could occur under pier and abutment foundations. To overcome this problem, compaction grouting was utilized, to treat the foundation soils.

Various reinforced earth retaining walls were constructed in Glenwood Canyon to accommodate for the possible large differential settlements of the foundation soils. The first time these walls were constructed with 10-foot wide and 20-foot high fascia panels. These panels admirably withstood severe differential settlements. However, they did not meet the specifications for the final alignment due to the horizontal rotations associated with the vertical...