[2] To confirm the presence of expansive clay soils, geotechnical engineers may perform laboratory testing techniques to assess shrink-swell potential.
A mineralogical analysis is an X-ray diffraction (XRD) test that can identify specific clay minerals, such as montmorillonite, which would indicate shrink-swell qualities of the soil.
[4] Field assessment for expansive soil may also be conducted, including a visual inspection to identify surface characteristics such as gilgai topography (alternating mounds and depressions) and deep shrinkage cracks.
These include designs that call for digging deep foundations or installing pile systems extending beyond affected soil depths and reinforced slab-on-grade construction with underlying crossbeams.
Strategies may include drainage systems and grading for surface water management, using sump pumps, impermeable vertical moisture barriers, and landscaping designs incorporating vegetation, moisture-regulating ground cover, and/or buffer zones around the structure.