Improving expansive clay beds with granular pile anchors (GPAs) and geogrid-encased GPAs

Granular pile anchors (GPAs) are an innovative foundation technique developed for reducing the heave of expansive clay beds. Other engineering characteristics of expansive clay beds have also been found to improve through GPA reinforcement. This paper presents experimental data on heave, compressive load response and pullout response of expansive clay beds reinforced with plain GPAs and geogrid-encased GPAs. The heave of the expansive clay beds decreased by 95·12% on the installation of plain GPAs and it further decreased (by 98·3%) in the case of geogrid-encased GPAs. Plate load tests were conducted on unreinforced expansive clay beds and clay beds reinforced with plain GPAs and geogrid-encased GPAs for a comparative study. Similarly, pullout tests were conducted on clay beds reinforced with plain GPAs and geogrid-encased GPAs. The clay beds reinforced with geogrid-encased GPAs resulted in a higher load capacity in compressive as well as pullout tests than the beds reinforced with plain GPAs.