Efficacy of granular pile-anchors in arresting heave in expansive soils

This paper presents the efficacy of a new foundation system in the form of granular pile-anchors in arresting heave in expansive soils. Compression-resistant granular piles are effective in improving soft clays and loose cohesionless deposits, where the chief problems are poor bearing capacity and large settlements. However, in the case of expansive soils, the problem is heave, and the uplift force exerted on the foundations is tensile in nature. To resist this, a granular pile needs to be modified into a granular pile-anchor wherein the foundation is anchored at the bottom of the pile to a mild steel plate with a mild steel rod. Because of this anchorage, resistance to uplift is developed along the pile-soil interface and consequently, heave is enormously reduced. The laboratory tests conducted to study the efficacy of this new concept yielded promising results, which are discussed in this paper.