Arizona's expansive soil problem is driven by the extreme moisture swings of the desert climate. Months of drought shrink high-plasticity clays to rock hardness, opening deep desiccation cracks through the soil profile. When monsoon rains arrive, water pours into these cracks and reaches clay minerals at depth simultaneously—triggering rapid, powerful swelling that heaves roads, cracks foundations, and shears utility connections. The Phoenix metro, Tucson, and Flagstaff areas all contain significant expansive clay deposits.
ADOT and Arizona municipalities spend millions annually repairing expansive soil damage on highways, water mains, sewer lines, and commercial facilities. Arizona's clay damage is particularly aggressive because the monsoon delivers moisture so quickly to deeply desiccated soils—creating swell pressures that exceed those in more humid climates where moisture changes occur gradually.
GSI injects hydrated lime into Arizona's expansive clay formations, permanently converting swelling montmorillonite minerals into stable calcium silicate compounds. Arizona's deep desiccation cracks actually aid treatment—lime slurry penetrates deeper through the natural crack network than conventional mixing can achieve, reaching clay at depths where monsoon water triggers the worst swell events.
Structures already displaced by swell cycles need both stabilization and releveling. GSI installs helical piers through the expansive zone to non-expansive bearing material below, then hydraulically jacks the structure to original grade. Void forms between foundation elements and soil surface allow the untreated surrounding soil to continue its seasonal movement without affecting the re-supported structure.
For new construction on expansive sites, GSI designs pre-wetting and moisture conditioning programs that bring soil moisture to equilibrium before building—eliminating the first-cycle swell that damages structures built on desiccated clay without treatment.
Expansive soil treatment designed for humid climates fails in Arizona's extreme moisture environment. GSI engineers for the conditions Arizona actually presents:
One chemical treatment eliminates the swell cycle that costs Arizona millions annually. GSI's desert soil specialists design treatment calibrated to your site's specific clay and moisture conditions.
