Bridges

Monopile bridge foundations have the potential to significantly reduce construction costs compared to conventional pile group foundations. However, this bridge configuration leads to increased slenderness, lateral deflection, and a shift towards instability as the mode of failure before reaching material strength capacities. AS5100.5 mandates a nonlinear analysis for a sway frame when the lateral deflection of a compression member between end supports exceeds Lu/250 from linear elastic analysis. The absence of a specified lateral deflection limit in the code complicates the demonstration of design compliance. This paper aims to underscore design issues, the lack of a compliance demonstration mechanism, and propose a lateral deflection limit to ensure robustness by controlling the P-Delta effect.