Geosynthetics filtration

Similar to the filtration function, the requirements for drainage are soil retention, adequate flow capacity, and long term soil-to-geotextile flow equilibrium, in respect of minimum clogging of the pore spaces. Apart from the flow capacity within the plane of the geosynthetic material, the other aspects have been dealt with above. We will therefore now consider the inplane flow characteristics. 

Faure, Y. H, Gourc, J. P. and Gendrin, P. (1990), Structural Study of Porometry and Filtration Opening Size of Geotextiles , Geosynthetics Microstructure and Performance, Peggs, L. D., Editor, ASTM Special Technical Pubhcation 1076, pp. 102-119. 

Geosynthetics have been used in new road construction in various ways to minimise the previousiy mentioned probiems as weii as in the maintenance of existing paved roads (overiays appiied to strengthen existing pavements). In this category of application the two principal roles for geosynthetics are separation/filtration, and reinforcement. The use of geosynthetics to perform these functions in unpaved and paved roads is discussed in Section 5.1.3.1 and 5.1.3.2. 

The fields of application of geosynthetics can be eharacterised by the terms separation, protection, filtration, drainage, reinforcement, containment and sealing. 

Industrial applications of polyolefin fibers include woven and nonwoven geotextiles, agriculatural fabrics, construction sheeting, automobile fabrics, filtration media, rope/twine, woven bags, narrow-woven web and tapes, tents, and tarpaulins. Geosynthetic fabrics will continue to be a growing market for polypropylene nonwovens. 

Montero, C. M. Overmann, L. K. 1990. Geotextile filtration performance test. In Koener, M. (ed.) Geosynthetic testing for waste containment applications. ASTM STP 1081, American Society for Testing and Materials, Philadelphia. 273-284. 

The functions generally attributed to geosynthetic products are separation, filtration,... 

The types of geosynthetics used for drainage and filtration are usually different. 

Artieres, O., Tchemiavsky, J.G., 2002. Geotextile filtration systems for dams — 30 years of improvement. In Delmas, G., Girard (Eds.), Geosynthetics — 7th ICG. Swets Zeitlinger, Lisse, pp. 969—974. 

With the development of geosynthetics, great achievements have been made in improving foundation soils. As a result of this, nearly all functions of geosynthetics can be used reinforcement, separation, filtration, and drainage. 

The alternative pillow test was originated by Tom Stephens of Ten Cate in about 2005 (Ten Cate Geosynthetics, Inc., 2007) and formalized as a standard in 2009 (GRTGT15). The only related references in the open literature are the work of Professor Bhatia and her students at Syracuse University, who developed and conducted research on a similar test which they called the pressure filtration test (Bhatia and Liao, 2004 Satyamurthy et al., 2008, 2009). Hydraulic pressures were measured and quantitative data were produced but the laboratory configuration was different from the field-simulated pillow test, which is described subsequently. 

Yaman, C., Martin, J.P., Korkut, E., 2006. Effects of wastewater filtration on geotextile permeability. Geosynthetics International 13 (3), 87—97. 

Dynamic filtration A geosynthetic performs the function of dynamic filtration when the equilibrium geotextile-to-soil system allows for adequate liquid flow with limited soil loss across the plane of the geotextile over a service lifetime compatible with dynamic flows. 

Having geosynthetic components enables ECPs and SRDs to be more dependably engineered for specific project conditions. For example, geotextiles can be chosen with specific filtration and flow characteristics to prevent armor system undermining as an ECP or to retain sediments from runoff as an SRD. In other cases there may be a need for extended resistance to UV exposure or a requirement for sufficient strength to impound sediment-laden waters. 

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