2. Families of compressible soils

2.1 Nature of soils at risk

All soils are compressible, i.e. they settle when subjected to a load. In this section, we will not deal with soils that settle instantaneously as they are loaded, such as granular sandy soils that are more or less dry, or consolidated soils whose settlement has little influence on the stability of the structure.

The following is a non-exhaustive list of the most common hazardous materials. They include :

• peat (highly organic soils) ;

• silt (low-organic soils) ;

• soft clays, clayey or loose silts ;

• washing or settling sludge ;

• recent fill (anthropogenic...