A new static p‐y approach for piles with arbitrary dimensions in sand

When it comes to the general design of laterally loaded piles in offshore environments, bedding resistance is usually modelled by the p‐y method recommended in the offshore guidelines (OGL). Several investigations presented in the literature indicate that the head displacements of large‐diameter monopiles are underestimated for extreme loads but overestimated for small operational loads. An extensive evaluation of the OGL method is presented here using three‐dimensional numerical simulations. The evaluation has shown that the OGL method is not applicable for the design of large‐diameter piles. Moreover, modified p‐y formulations presented in the literature accounting for the effect of the pile diameter are also not generally suitable for piles with arbitrary dimensions and load levels. Therefore, the derivation of a new p‐y approach is presented in detail. The new approach consists of “basic p‐y curves” that are valid for a pile of infinite length exhibiting a constant horizontal deflection. In an iterative scheme, these basic curves are adapted depending on the pile deflection line and the pile length to account for a more realistic bedding resistance along the pile shaft. A comprehensive parametric study with 250 pile‐soil systems reveals that the new p‐y approach is able to predict the horizontal loadbearing behaviour as well as the local pile‐soil interaction quite realistically.