Experimental Modelling of Helical Piles under Axial Loading

Abstract


 Due to the rapid increase in population, the demand for high-rise buildings is also increasing daily. Researchers have performed various numerical and experimental studies to find out the best foundation type for structure. A helical foundation is one of the most suitable foundation types to be incorporated in the construction of high-rise buildings. In a helical pile, some fraction of axial load is taken by the helix, which increases the load-carrying capacity of the foundation. This study is carried out to determine the settlement and load carrying capacity of the helical pile and helical pile raft cohesion-less soil. For this study, a small-scale model of a helical pile and helical pile raft foundation is prepared and fitted in the rectangular shear box filled with cohesion-less soil (sand). Testing on single helix piles, double helix piles, two helical pile rafts, and four helical pile rafts has been conducted. Instrumentation of the model is carried out using a settlement transducer and load cell to note down the settlement and load applied, respectively. Results provided that the maximum axial load carrying capacity of a single helix pile is almost 1200N at a settlement of 25mm while that is 1750N, corresponding to a 25mm settlement for a double helix pile. Similarly, the maximum load carrying capacity for two helical pile rafts and four helical pile raft are 2700N and 4400N, respectively, at 25mm. These results were compared, and a double helix pile has a greater load-carrying capacity than a single helix pile. Similarly, a pile raft with four helical piles has a greater load-carrying capacity than a pile raft consisting of two helical piles.