Augmentation of Pile Performance by Optimizing Pile Dimensions Under Frequency-Dependent Coupled Vibration

This study aims to comprehend the effect of pile dimensional variations and to elucidate the superior pile dimension under frequency-dependent coupled vibration. The study performed field vibration tests on two different sets of piles to understand the effect of diameter and length alterations, by assuming a 90 mm diameter pile of 1.7 m length as the standard pile. The first set of piles, say Phase 1, deals with a 35 % dimension decrement as compared with the standard pile (60 mm diameter pile of 1.7 m length and 90 mm diameter pile of 1.1 m length), whereas Phase 2 deals with a dimension increment, as compared with the standard pile (114 mm diameter pile of 1.7 m length and 90 mm diameter pile of 2.3 m length). As a preliminary investigation, site characterization was done using both in situ and laboratory testing. Forced vibration tests were conducted in the field on all five piles for five different chosen eccentric moments (0.131, 0.186, 0.214, 0.241, and 0.304 Nm) under a static load of 5 kN. The responses were acquired in terms of frequency-amplitude responses, and the plots show two prominent peaks and nonlinear behavior. The responses showcased that the diameter alteration of piles exemplified a prominent role in the dynamic performance of the pile as compared to length increment. Finally, this research underscored that prioritizing pile diameter is more effective for optimizing pile performance in scenarios involving coupled dynamic loading.