Abstract: Relying on the bridge pile foundation project in the salt marsh area of the De Xiang Expressway in Qinghai Province. To investigate the influence of different corrosion damages on the bearing capacity of foundation pile in salt marshes, a response model of the vertical and horizontal bearing capacity of foundation pile was established using the response surface method, considering factors such as pile length, pile diameter, corrosion depth, and spalling thickness. The interaction between two factors was analyzed using response surface plots. The results show that the accuracy of the corrosion-damaged foundation pile bearing capacity model established by the response surface method is relatively high. The vertical bearing capacity increases with the increase of pile length and pile diameter, and the decrease of corrosion depth and spalling thickness. The horizontal bearing capacity increases with the increase of pile diameter and the decrease of spalling thickness, but first decreases and then increases with the increase of pile length. When the pile length is relatively small, the influence of corrosion depth on bearing capacity is relatively small, while the influence of spalling thickness is much greater. Therefore, attention should be paid to the protection against horizontal corrosion damages in engineering practice.

Key words: response surface methodology, foundation pile, bearing capacity, salt marsh, corrosion