Model tests and theoretical analysis were performed on dumbbell pile

which was developed by Geotechnical Research Institute of Hohai University.The tests were carried out to detect the differences in pile′s bearing capacity

pile toe force

pile head force and settlement between piles with or without pile cap or expansion pile head.It was found that if the model shaft was filled with sand

the pile head force shared most of dumbbell pile′s bearing capacity

so dumbbell pile could be regarded as end-bearing pile in design.Compared with other piles with normal section types

dumbbell pile had larger bearing capacity and less pile top settlement.Formula for dumbbell pile′s bearing capacity was also put forward

which was confirmed by the experimental data.