The integral abutment jointless bridge (IAJB) has lots of advantages

so it has been widely used in western countries. The pile foundation of IAJB requires higher horizontal deformation capacity. H-beam steel piles are often used to construct integral bridges in the west

while RC piles are mainly adopted in China. Lots of studies and engineering examples show that the application of RC piles can meet the deformation requirements of IAJBs

but the influence of the earth pressure behind abutment on RC piles is not clear. Therefore

based on a practical IAJB in China as an engineering background

with certain RC pile reinforcement ratio and the shape of the section as parameter

four integral abutment-RC pile test models were designed. The reciprocating low-cycle pseudo-static test on interaction of integral abutment-H-shaped pile-soil was carried out to study the hysteretic behavior

lateral deformation law and interactive mechanism. The test results show that under the reciprocating displacement loading

the soil behind the abutment will be emptied

and the failure positions of the specimens are mainly concentrated at the connection between the bottom of the abutment and the top of the pile. Increasing the reinforcement ratio of RC piles or using rectangular section RC piles can lower the failure positions and improve their mechanical properties. The hysteretic curve of the integral abutment-RC pile-soil system is full in the first quadrant

indicating better energy dissipation capacity

while the third quadrant hysteretic curve has a smaller covering area. The experimental results also show that the abutment movement can be regarded as a rigid displacement with rotation

and under the action of reciprocating displacement beyond the limit of elastic deformation

the abutment and the pile appear obvious cumulative deformation. Besides

the relative angle between abutment and pile head increases as the damage degree increases. Accordingly

by increasing the reinforcement ratio of RC piles or adopting rectangular section RC piles

1) the energy dissipation capacity of the whole bridge-RC pile-soil system can be increased; 2)the elastic cracking displacement of RC piles can also be increased

which leads to its later yield and failure and increases the bearing capacity of the whole system; 3) the stiffness degradation rate and degradation amplitude of the system are significantly reduced; 4) the failure of bridge abutment and pile joint

along with the accumulated deformation

can be effectively reduced.