Each year, billions of dollars in damage to building foundations and structures is caused by shrinking and swelling behavior caused by clay soil.
In fact, expansive clay soil is the most predominant geologic hazard across the U.S. Several geotechnical solutions can alleviate these problems. On new construction, the options are: removal and replacement, capping or burying the expansive material, and treatment with hydrated lime. Structural solutions in new construction include upgraded structural slabs (post-tension, waffle, mat) or elevated slabs supported on deep foundations.
For an existing structure, a forensic geotechnical study is needed to identify and quantify damages, assign causation, and make appropriate recommendations for remediation. Moisture control may be a suitable option for remediation and it is a design requirement for new construction.
In extreme cases, helical anchors and slab (mud) jacking or removal and reworking of soil below an existing structure is necessary. For paved surfaces, expansive clay soils can be remediated with thicker sections of asphalt, reinforced concrete pavements, and lime treatment.