Vertical Drain: Sand Pile/Sand Drain Construction
In the 1930s the first reasonable application of vertical sand drains was made in California. In Sweden, during the same decade, Kjellman introduced the first prototype of a prefabricated vertical drain made entirely of cardboard (Jamiolkowski et al., 1983). Subsequently, several types of prefabricated vertical drains were developed which are basically consisting of a plastic core with a longitudinal channel wick functioning as a drain, and a sleeve of paper of fibrous material as a filter protecting the core.
Sand Pile Construction Gallery
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What is the Sand Pile (Sand Drain) Installation Procedure?
- 1 Sand drains are basically boreholes filled with sand.
- 2 For the displacement type of sand drains, a closed mandrel is driven or pushed into the ground with resulting displacement in vertical and horizontal direction.
- 3 The installation causes therefore disturbances, especially in soft and sensitive clays, which reduces the shear strength and horizontal permeability.
- 4 The low- or non-displacement installations are considered to have less disturbing effects on the soil.
- 5 Drilling of the hole is done by means of an auger or water jets. In terms of jetting, however, installation is very complex.