PI: Spencer Quiel

University: Lehigh University

Many civil structures utilize deep steel beams (e.g. plate girders) with thin webs, which are susceptible to buckling under shear load. It has been demonstrated that web plates which elastically buckle due to shear load still possess a significant amount of postbuckling shear strength, which is a phenomenon currently considered in the design of plate girders.

The PI, together with collaborators from High Steel Structures, LLC and Princeton University, is currently engaged in an NSF-funded research project to comprehensively investigate the mechanics of web-shear buckling behavior in steel plate girders. The goal of that project is to develop (a) predictive models that capture the true mechanics, and (b) design modifications which increase economy, robustness, and life-cycle performance.

The proposed PITA project will directly leverage the results of the NSF-funded effort to investigate the influence of initial imperfections (both their magnitude and shape) on the shear performance of slender webs in plate girders. Current design criteria have an assortment of imperfection limits for these elements, but the mechanical basis for their usage is unclear. The PI will work closely with High Steel to evaluate imperfection magnitudes and patterns that are typical to the girders that they produce, thus providing a tangible evaluation of realistic imperfections on shear performance. A reliability-based evaluation will be performed using field measurements, which will then be stochastically sampled for parametric finite element analyses. The results of this project can be beneficial to steel fabricators and designers toward continued innovation in thin web steel plate girder construction. The results of this project can also give more confidence to DOTs and bridge designers when determining the impact of web imperfections that are evaluated during girder inspections.