Lateral load response of steel fiber reinforced concrete model piles in cohesionless soil

It has been long recognized that piles could be damaged under major lateral loading environments. Precautions such as increasing pile dimensions or reinforcement to avoid damages were often proved to be inadequate for satisfactory pile design especially against heavy lateral loads. This fact necessitated research for piles that are more resistant to lateral forces. Recent debate for better lateral load performance has been about the design and construction of ductile piles. In this respect, steel fiber reinforced concrete (SFRC) can be considered as a contemporary material being able to provide desired additional ductility to conventional reinforced concrete (RC) piles. The lateral load carrying mechanisms of SFRC piles and their interaction with surrounding soil have not been fully studied yet. In this study an investigation for lateral load carrying capacity of SFRC piles in cohesionless soils has been undertaken. A model study involving instrumented model piles, a testing pool and a monotonic loading mechanism has been planned and pursued. Three different steel fiber ratios by volume were utilized in the production of model piles. Performances of these piles were compared with that of the conventional concrete pile. The goal was to observe the influence of steel fibers on ductile pile behavior by isolating them from other reinforcement components (i.e. bending and shear reinforcement). It has been found that SFRC model piles with steel fiber reinforcement ratios of 1% and 1.5% are capable of providing more ductility and higher lateral load carrying capacity while taking lower bending moments compared with the concrete model pile.