<p><p><figure id='attachment_8065' style='max-width:743px' class='caption aligncenter'><img class=" wp-image-8065" src="https://www.geoinstitute.org/sites/default/files/geotech-tools-uploads/…; alt="Schematic section view of a pavement edge drain made using a prefabricated geocomposite edge drain." width="743" height="573" /><figcaption class='caption-text'> Prefabricated geocomposite edge drain (PGED) (Koerner et al. 1996).</figcaption></figure></p><p><div><h2>Project Summary/Scope:</h2>The purpose of the project was to demonstrate the long-term performance of geosynthetic highway drainage systems by excavating 91 field sites in seventeen states throughout the United States. Sites involve the following geosynthetic drainage applications:<br><ul> <li>Prefabricated Geocomposite EdgeDrain (PGED)</li> <li>Geotextile-Wrapped UnderDrain (GWUD)</li> <li>Perforated Pipe UnderDrain (PPUD)</li> <li>Geotextile-Socked Perforated Pipe (GSPP)</li> <li>Geotextile Wall Drain Filter (GWDF)</li> <li>Geotextile Erosion Control Filter (GECF)</li></ul>A particular site was selected and traffic control was provided by the DOT. A 1-meter wide by 2-meter long by 1.2-meter deep pit was excavated in the shoulder adjacent to the existing highway. The shoulder soil and the underlying base soil were excavated with a hand-held pneumatic breaker. The subgrade was then excavated with a smaller pneumatic clay spade and hand shovel. The geosynthetic drainage material was sampled using a 62-mm diameter Shelby tube sampler in two or three sections. The tube was driven horizontally by a sledgehammer through the edge drain cross section to trap the geotextile and adjacent soil maintaining its interface. The Shelby tube samples were then sealed, capped, brought back to the laboratory, and air dried. After a week of drying, the samples were infiltrated with a bright yellow-colored resin epoxy and allowed to set for two days. After hardening, the samples were cut with a diamond saw and inspected under a microscope. Each site was video-taped and photographed throughout the excavation and sampling process. After completion of the excavation process, the drainage system was repaired under the inspection of the local highway engineer or other designated individual for proper functioning. After the repair work was approved, the excavation was backfilled and compacted. The highway shoulder was then allowed for service and traffic control was released.<br><h2>Performance Monitoring:</h2>GWDF and PPUD had an acceptable degree of long-term performance. Remaining four drainage systems did not perform effectively due to some installation and maintenance problems.</p><p>High clay concentration in backfill soils, unbalanced outlet elevation, vegetation and soil around outlet, outlet pipe damage, no sealant between pavement and drainage, small cross section of drain, and guard post penetration into the drain were the major sources of construction and maintenance problems.</p><p>Use of improper product, excessively deformable core, installation damage, use of asphaltic drain pipe without perforations, excessive soil clogging, and excessive UV degradation were problems related to drainage and filter components.<br><h2>Case History Author/Submitter:</h2>Geosynthetic Institute<br>475 Kedron Avenue<br>Folsom, PA 1903<br><h2>Project Technical Paper:</h2>Koerner, G.R., Koerner, R.M., and Wilson-Fahmy, R.F. (1996). “Field performance of geosynthetic highway drainage systems.” <em>ASTM Special Technical Publication,</em> 165-181.<br><h2>Date Case History Prepared:</h2>November 2012</p><p></div></p></p>