The purpose of this paper is to present the behavior of large diameter precast group piles subjected to lateral load. The group piles were constructed for in-site tests a study for High Speed Railway foundation. The site selected for testing was located at Taibao, Chiyi, Taiwan. All lateral tests were finished on June 28,1997. In this study, the p-y curve method and Poulos's elastic method are selected to analyze lateral load-displacement behavior of a single pile, Poulos' elastic method and hybrid approach are used to analyze lateral load-displacement behavior of group piles. The results of comparing the data calculated form the suggested methods with those of measuring in the pile loading test, show that a good agreement is obtained in the study.
To support the upper structure, pile is one of the most commonly used foundation modules in civil engineering. The pile is used to support axial loading, lateral loading, and moment transferred from the upper structure. The main causes of the lateral forces are wind, wave, traffic volume, and earthquake, etc. Many experiments and analytic studies have been done to investigate the behavior of pile subjected to lateral loading. Unfortunately, most of the studies so far focused only on the single pile while relatively few studies have been performed on group piles. However, in practice, only group piles are used in foundation engineering. Hence, it is necessary to further explore the behavior of the group piles. To obtain the proper result, the interactions among soil, pile, and pile cap have to be put into consideration in analyzing the behavior of group piles. The difficulty of this analysis further increases due to the nonlinearity of the soil behavior. The p-y curve method is usually applied to analyze the deflection of a single pile non-linearity behavior.
