Investigating Load-Settlement Characteristics of Square Model Footings on Sand Beds Enhanced with Textured Vertical Pultruded Fiberglass Reinforced Helical Piles

Abstract

This article introduces a novel ground enhancement method utilizing textured vertically oriented fiberglass pultruded pipes. These pipes feature a widened bottom toe in a helical shape. The research primarily explores textured prefabricated helical piles, varying in length and cross-sectional area, designed to act as reinforcing bearing elements in sandy soil. The ongoing study includes performing experimental investigations on a laboratory model square footing positioned on sand, with textured PFRH piles installed beneath it. A parametric investigation was carried out to examine the influence of textured PFRH pile slenderness ratio, different states of sand beds, and varying helical plate diameters through laboratory model plate load tests. The findings indicated that placing textured PFRH piles beneath the footing substantially enhanced the settlement characteristics and load-carrying capacity of the structure. There was a noticeable increase in load-carrying capacity with an increase in the slenderness ratio of textured PFRH piles, although the improvement became insignificant beyond a slenderness ratio of 20. In the absence of reinforcement, denser sand exhibited superior bearing capacity for footings. However, in the case of reinforced footings, textured PFRH piles demonstrated the most substantial improvement in medium-density sand. Furthermore, augmenting the helical plate diameter led to an enhanced load-carrying capacity. The study employed multivariate linear regression to establish a robust correlation between experimental and predicted bearing capacity ratios, affirming the reliability of the findings. In summary, this research underscores the significant potential of utilizing textured prefabricated helical piles in fortifying soil foundations, offering valuable insights for optimizing the design and performance of such systems across diverse soil conditions.