How do you determine the spacing and depths of the wick drains?
The first thing that needs to be done is a geotechnical investigation to determine the soil types and the compressibility properties of the soil. The wick drains generally, but not always, extend through the compressible layers. The amount of settlement under the design load, as well as the time required, can then be determined after the geotechnical properties are known. Once this information is determined, the wick drain spacing can be calculated using established analytical techniques, such as discussed in the Technical Topics section of this website.