GEOTEXTILES AS REINFORCEMENT Q: I read a research paper on strengthening of clay beds by providing granular piles reinforced with horizontal geotextile. But there is no mention of the mechanism of geotextile, which decreases settlement. Please help me in this regard. A: The geotextiles over granular piles act as reinforcement. The geotextile and geogrids are shaped like a catenary spanning the columns and supporting the soil above. One can search load transfer platform, basal reinforcement or geosynthetic encased column for more. In regard to specific references on the subject, I would search Carlsson 1987, Kempfer 2004 or Collin 2005. A key concern with the technology is the stress concentration and the pile/column caps. I would suggest you consider a rounded precast pile cap on rigid piles or shafts. Such caps are not necessary on granular piles, which do not have defined boundaries. SEAMING DISSIMILAR GEOMEMBRANES Q: I kindly request your technical support in the questions below: A nonpolyethylene geomembrane was used in phase 1 of the tailings dam waterproofing system of a gold mine. For the expansion (phase 2), the use of a high-density polyethylene (HDPE) geomembrane is being evaluated. How can the HDPE geomembrane join the bituminous geomembrane from the previous phase? What is the recommended procedure in cases like this? A: The seaming of dissimilar geomembranes is typically achieved with a stability berm that delineates the two projects and geosynthetic clay liner (GCL) between the two geomembranes. One may need to run stability analysis if this connection is on a side slope. G Welding and testing equipment for the serious geosynthetics installer Pro-Wedge VM-20 Wedge Welder Over 6,000 units sold! Pro-Tester High-Pull Tensiometer for testing high-strength materials with new Auto-Engage feature (888) 324-WELD (9353) or 530 621-3200 Visit demtech.com or call for more product information. www.GeosyntheticsMagazine.com 0820GS_cv2-13.indd 13 13 7/22/20 11:21 PMhttp://www.demtech.com http://www.GeosyntheticsMagazine.com