Drainage hydraulic properties

With the needle-punched nonwoven geotextiles, the water can move in both the vertical and horizontal directions. The nonwoven geotextiles can provide a drainage function by transmitting liquid within the plane of their structure. This means the flow is predominant in the lateral direction, and this is important in assessing the in-plane hydraulic properties (Kopitar, Skenderi, Rukavina, 2014). 

Pak, A., Zahniatkesh, Z. (2011). Experimantal study of geotextiles drainage filtration properties under different hydraulic gradients confining pressures. International Journal of Civil Engineering, 9(2), 97—102. 

This section provides a general overview of the properties of lake systems and presents tlie basic tools needed for modeling of lake water quality. The priiiciptil physical features of a lake are length, depth (i.e., water level), area (both of the water surface and of tire drainage area), and volume. The relationship betw een the flow of a lake or reserv oir and the volume is also an important characteristic. The ratio of the volume to the (volumetric) flow represents tlie hydraulic retention time (i.e., the time it would take to empty out the lake or reservoir if all inputs of water to the lake ceased). This retention time is given by the ratio of the water body volume and tire volumetric flow rate. 

The main design aspects of hydraulic fills are discussed in the previous chapters which mainly focus on the geomechanical properties of the fill mass and subsoil. There are, however, more design aspects such as drainage, wind erosion and slope protection that require attention as well. Although this Manual will not discuss these aspects in detail, an overview and relevant references will be presented. 

Finally, the geotextile must have the required filtration/hydraulic characteristics to provide the coincident functions of separation, filtration, and drainage. Properties required for separation and filtration functions are related to opening characteristics... 

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