Behavior of pile group incorporating dissimilar pile embedded into sand

Piles are recommended to transfer the superstructure loads safely through soil by friction resistance and end bearing into firm bearing stratum. Piles drive their load via weak soil into competent bearing stratum. Piles in group are designed of similar length, diameter and working load. Except in special cases such as raft on piles which may be attentionally of different lengths. Dissimilarity in piles within a group may result from uncertainties in soil conditions, or imperfection in pile construction. Soil conditions may force the designer to design pile groups in a building having different lengths. Studying the behavior of pile groups incorporating dissimilar piles, in literature is scarce. The paper is devoted to study, through small scale models in laboratory, the behavior of pile groups incorporating one dissimilar pile. The aim of the research work was to emphasize the effect of dissimilar pile on the behavior of pile group through load settlement relationship. The study revealed that the end bearing of the group due to the existence of dissimilar pile, decreases as the number of piles in the group increased. The deficiency of two-pile group containing one dissimilar pile attains 90%, while in a group containing 9-piles it reaches 5%