The three-dimensional elastoplastic finite element method is adopted to study the behavior of laterally loaded PCC pile groups.Lateral bearing capacity and pile group efficiency of PCC pile are compared with equalarea solid circular pile.Critical pile spacing on group effect of PCC pile is obtained.The effects of pile spacing

number of piles

and restrained condition of pile top on PCC pile group efficiency are analyzed.The study results show that lateral bearing capacity of PCC single pile and PCC pile group are larger than that of equalarea solid circular pile.Longitudinal and transverse critical pile spacing on group effect of PCC pile group are 7.4 and 2.8 times of external diameter respectively.Pile group effect of PCC is more obvious with smaller pile spacing and larger number of piles.Pile group efficiency must be considered when pile spacing is less than the critical value.There is great difference in distribution of bending moment along PCC pile and lateral bearing capacity between fixed and articulated pile top.Behavior of PCC pile can also be coordinated by changing constraint condition of pile top.