Challenges in Large-Diameter Bored Piling in Coralline Rock Formations

While the Indian subcontinent has undergone substantial development in major infrastructure over the past decades, the smaller islands around India are just beginning to undertake major projects. These islands are predominantly archipelagos with coralline geology. Coralline rocks have unique characteristics, which are unlike those of conventionally formed rocks from igneous, sedimentary, or metamorphic origin. From a formation and mechanical point of view, these rocks are soft, porous, karstic (including very large cavities), and have low strength. Major infrastructure often requires deep pile foundations in these coralline rocks, which are to be constructed under environmental restrictions and requiring meticulous construction staging to reduce disturbance to rocks mass. This paper addresses the challenges faced in designing and executing large-diameter bored piles in coralline rock formations.