Compared with traditional equal section pile

belled wedge pile has advantages of high unit material utilization

large pile side friction and tip resistances. However

there is little research focused on the quantitative model test on its vertical and lateral bearing capacities The bearing capacities of belled wedge pile embedded in sand under vertical load

lateral load

and surcharge load are tested experimentally to measure the pile shaft

tip resistances

lateral earth pressure

down-drag displacement

and drag load. At the same time

the bearing capacities of equal section pile with the same concrete usage are compared. The mechanism and differences of these piles are preliminary discussed. The results show that the vertical compressive bearing capacity of belled wedge pile are nearly 2.33 times that of equal circular pile

the side and tip resistance are higher than circular pile; the lateral bearing capacity of belled wedge pile is nearly 1.48 times that of circular pile

the larger diameter of the upper part of belled wedge pile and the expanded tip improve the lateral bearing capacity. Comparing with circular pile

the wedge angle can effectively reduce the down-drag displacement of pile top. It presents as one effective ways to reduce the negative friction resistance to the pile foundation by converting the traditional pile type into the belled wedge pile.