Model test study on horizontal bearing characteristics of foundation piles in high and steep slope areas

There are more and more diseases caused by the horizontal action of bridge foundation piles built by experience in high and steep slope areas. In this paper, a set of loading devices and test scheme were designed with the Hongding bridge as the prototype. Considering the position of the foundation piles in the slope and the stress form, the horizontal static loading and lateral-axial combined loading model tests were conducted on the horizontal bearing characteristics of the foundation piles, and the fitting relationships of the pile top displacement, the horizontal load, the relative position and the vertical load were obtained, respectively. The results show that under the horizontal cyclic load, the horizontal displacement of the pile top and the bending moment of the pile body increase with the increase of the load and the load cyclic action times. Under the horizontal load, the ultimate bearing capacity of the foundation pile is inversely proportional to the horizontal distance between its position and the slope toe. That is, the closer the foundation pile is to the slope toe, the greater the ultimate bearing capacity, while the horizontal displacement of the pile top and the bending moment of the pile are smaller. The influence of simultaneous horizontal and vertical loading on the horizontal ultimate bearing capacity of the pile foundation is related to whether the pre-added vertical load reaches the critical value of the stable vertical deformation load of the foundation piles. When the vertical load is less than the critical value, the horizontal ultimate bearing capacity of the foundation piles can be increased; When the vertical load is greater than the critical value, the horizontal ultimate bearing capacity of the foundation piles would be reduced. © 2022 Academia Sinica. All rights reserved.