Development of a Mixed Numerical Method for Piled-Raft Analysis Using International Codes

Abstract

In previous research (El-Gendy et al., 2013), the authors presented a modified hyperbolic load-settlement model for bored piles, which depends on the ultimate loads predicted by relevant international codes (ECP202, 2005; DIN4014, 1990; AASHTO, 2005; French Code, 1993). This research presents a mixed numerical method to analyze vertically-loaded piled-rafts comprising large-diameter bored piles. To determine the stiffness matrix of piled-raft, the pile-self settlement is simulated by using any of the four indicated codes or by the modified load-settlement model. Interactions among the different components of the piled-raft system are found using the elasticity theory. Analysis is performed iteratively until compatibility among raft, pile, and soil is ensured at all interfaces. The validity of the proposed method is established by comparing the predicted settlements and pile load ratios to field measurements for nine published case histories. The results showed that DIN4014 mostly gives the closest match to field measurements.