Retaining Structure Selection at Project Level

With recent advances in retaining structure technology, the retaining structure selection process has become increasingly complicated. Because of the potential for cost savings, the benefits of optimizing the selection process are significant. Eight state departments of transporta­ tion (DOTs) are characterized in terms of how they select and analyze designs of, and obtain subject-matter expertise on, retaining structures. Results indicate most retaining structure types are specified by DOT engineers, including those designed by engineering consultants. However, 90 percent of the DOTs select only retaining structures for which they have in-house design expertise. The rational is presented for DOTs to have design expertise within their agencies for the full range of retaining structure technologies available if they are to select optimal structure types.