Desiccation in Cohesive Soils
Plant roots remove moisture from the surrounding soils. In cohesive soils (i.e. clay) this can lead to the soil becoming dry and shrinking which can cause damage to buildings and cause subsidence. The reverse of this is also true, removing large plant roots (e.g. removing a tree) can cause an increase in moisture in the soils which will lead to swelling in clay. This leads to heave which can also damage buildings.
Initial desk study repost can highlight the potential of soils at a site to exhibit these traits through assessment of the geology and historical features of the site. This is then followed by an intrusive ground investigation which allows soil properties to be characterized through laboratory and in situ testing. The results of these tests then help guide final design proposals for the future construction to minimise risk of damage to buildings.