Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Advances in HDPE barrier walls
To mitigate concerns expressed over vertical barrier walls consisting of soil-bentonite, soil-cement, cement-bentonite or soil-cement-bentonite backfilled materials, the use of a geomembrane is viable alternative. The paper describes five techniques for geomembrane installation as vertical barrier walls. In all of them the type of backfill material in the remainder of the trench space not occupied by the geomembrane is a site specific design decision. Contrary to geomembranes placed horizontally and fusion welded together, vertical geomembranes are usually joined by a 'lock and key' type of connection. The connections are made leak proof by use a hydrophillic gasket or grout seal. The paper also discusses at length the issue of diffusive permeability of HDPE geomembranes in a vertical barrier application. While it is not zero, it is extremely low for water (approximately 0.006 g/m2-day or 0.006 gal/acre-day) and is even very low for aqueous solutions of organic solvents. Data from the literature in this regard show a worst case situation of toluene at a concentration of 100 mg/l will diffuse less than 1 pint of liquid per acre of wall per day. Attenuation of such a small quantity in a low permeability soil backfill behind the geomembrane is readily achievable. Alternatively, it is even conceivable that a sand backfill (perhaps between two geomembranes as a leak detection system) could be utilized to pump seepage from behind the barrier in cases of extremely high environmental sensitivity.
Advances in HDPE barrier walls
To mitigate concerns expressed over vertical barrier walls consisting of soil-bentonite, soil-cement, cement-bentonite or soil-cement-bentonite backfilled materials, the use of a geomembrane is viable alternative. The paper describes five techniques for geomembrane installation as vertical barrier walls. In all of them the type of backfill material in the remainder of the trench space not occupied by the geomembrane is a site specific design decision. Contrary to geomembranes placed horizontally and fusion welded together, vertical geomembranes are usually joined by a 'lock and key' type of connection. The connections are made leak proof by use a hydrophillic gasket or grout seal. The paper also discusses at length the issue of diffusive permeability of HDPE geomembranes in a vertical barrier application. While it is not zero, it is extremely low for water (approximately 0.006 g/m2-day or 0.006 gal/acre-day) and is even very low for aqueous solutions of organic solvents. Data from the literature in this regard show a worst case situation of toluene at a concentration of 100 mg/l will diffuse less than 1 pint of liquid per acre of wall per day. Attenuation of such a small quantity in a low permeability soil backfill behind the geomembrane is readily achievable. Alternatively, it is even conceivable that a sand backfill (perhaps between two geomembranes as a leak detection system) could be utilized to pump seepage from behind the barrier in cases of extremely high environmental sensitivity.
Advances in HDPE barrier walls
Fortschritte bei Sperrwänden mit HDPE-Geomembranen
Thomas, R.W. (Autor:in) / Koerner, R.M. (Autor:in)
1995
14 Seiten, 9 Bilder, 3 Tabellen, 13 Quellen
Aufsatz (Konferenz)
Englisch
Advances in HDPE Barrier Walls
| Online Contents | 1996
Advances in HDPE barrier walls
| Tema Archiv | 1996
Advances in HDPE Barrier Walls
| British Library Conference Proceedings | 1996