Abstract: Considering the fact that the super-long pile groups are used very often and lucubrated less, three pile group models with deferent pile spaces are designed and done. Based on the model test data of super long-pile groups, the load transfer mechanism and the bearing behavior are analyzed. The relations between the pile group efficiency and pile spacing, between the pile capacity and pile spacing and between the skin friction and pile spacing are obtained. Through the axial force of super-long pile, the valid length problem is researched into. Results above are provided as important references to the theoretical research and technical application of super-long pile groups.

Key words: model test, super-long pile group, Q-S curve for super-long pile group, valid length of pile group, pile group efficiency