Prior to 1989, highway edge drains were backfilled with the existing trench material and dynamically compacted with a tamping shoe. The net result was damage to the inner core of the edge drain.

In response to these problems the installation specification was revised in 1989 to insure the integrity of the drainage system. The revised method of installation consisted of moving the panel to the shoulder side of the trench and then flushing a sand slurry into the trench for backfill. Flushing the sand eliminates the need for mechanical compaction.

Since 1989, two projects have been completed using the revised special note for installation and another is currently under construction. This report discusses the performance of these installations.

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Revised August, 1991.

The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of University of Kentucky, the Kentucky Transportation Cabinet, nor the Federal Highway Administration. This report does not constitute a standard, specification, or regulation. inclusion of manufacturer names and trade names are for identification purposes and are not to be considered as endorsements.