Field tests on bearing behavior of double pipe piles under horizontal load in Yellow River alluvial plain

During the past decades, the design of horizontal bearing pipe piles has still referred to that of bored piles, as a result, the conservative design has been found frequently. In order to get the bearing mechanism and pile group effect coefficient of double pipe piles under horizontal load, field tests are carried out. The test results show that the bearing capacity of double piles are larger than the calculated results from the China's Technical Code for Building Pile Foundations. The Coefficients of pile group effect of model tests are approximately 1.20 to 1.35 times than the calculated results from the Code. The research results are useful for the design of pipe piles under horizontal load in the same areas.