1. Part 4 MITIGATION OF FOUNDATION PROBLEMS ON EXPANSIVE SOILS

2. Schemes employed to combat expansive soils Schemes employed to combat expansive soils

3. Solutions for Expansive Soil Problems An alternative method for handling highly expansive soils using mass grading is to cover them with 15 feet of select non- expansive fill, as sketched here.

4. Theory of Drilled Piers Drilled piers and grade beam foundation systems must extend below the zone of seasonal moisture variation, which can be difficult to predict with any meaningful certainty, because it often depends on landscape watering by the homeowner

5. Drilled piers are intended to extend below the zone of seasonal moisture fluctuation, holding the structure down, when lightly loaded elements are subjected to moisture absorption and heave.

6. Many factors can contribute to poor foundation performance in areas underlain by expansive soils Most of these are beyond the control of the geotechnical engineer who was associated with the foundation recommendations

7. Geotechnical engineers must design redundant support systems; sufficiently robust so as to resist long-range human and environmental factors beyond their control, such as water leaks and abnormally wet weather.