Hydraulic properties, behavior, and testing of geotextiles

Mediterranea University of Reggio Calabria, Reggio Calabria, Italy 

Hydraulic properties of geotextiles are especially important for applications in which the geotextile has the function of a filter or drain. In these cases hydraulic requirements must be met. These requirements are typically retention, clogging, and hydraulic conductivity for filters and the transmissivity for drains, in addition to other specrhc requirements of the project. 

Geotextiles and other geosynthetics installed to transmit hquid in their plane provide a drainage function. 

Drainage can be defined as follows a sod—geotextile system in equilibrium that allows for adequate liquid flow with limited soil loss in the plane of flie geosynthetic over a lifetime of service compatible with the apphcation under consideration (Koerner, 2005). Therefore, drainage function refers to the flow of water or other fluids along the geosynthetic plane (transmissivity or in-plane permeability). 

According to the filtration function, a geotextile filter must be able to retain fine particles of base soil (retention criterion) and avoid the development of excessive pore water pressure on a soil geotextile interface (ie, fi ee flow of liquid through the geotextile plane) (permeabihty criterion). 

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The key properties of geotextiles used in reinforced soil applications are introduced with short explanations. For details about the tests mentioned here, see chapters Hydraulic properties, behavior and testing of geotextiles Long-term geotextile degradation mechanisms and exposed lifetime predictions and Geotextiles used in separation. 

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