Year: 2004
Type: report
Abstract: This research was conducted under four study phases. Phase 1 involved a full scale laboratory study to evaluate three different underdrain pipe and envelope systems. It was found that an open graded FA-4 envelope material without a geotextile wrapped pipe was a viable design option. In Phase 2 a study was conducted to relate the pipe slot size to the envelope gradation. A testing procedure was developed. A 2 mm pipe slot prevented FA-4 envelope material from passing into the pipe. In Phase 3 it was found that a modified FA-4 material with control of the 0.075 mm aterial could be produced which would have an acceptable saturated hydraulic conductivity value for good subdrainage performance. The study in Phase 4 was inconclusive in terms of selecting geotextiles that would not clog in subdrainage applications. Neither the Gradient Ratio Test nor the Hydraulic Conductivity Ratio Test identified conclusively whether soil-geotextile combinations would clog in the field.
Authors: Jeffrey S. Stein, B J Dempsey
Language: English
Subfield: Civil and Structural Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W615015571