Editor’s Note

Every paper published in the Journal is carefully vetted by the Editorial Board and selected for publication based upon an assessment of the original technical advancement(s) that it makes. Among all the exceptional papers selected for publication, a few stand out for their extremely high quality and unique contribution to the state of the art in structural engineering. These papers are tagged by reviewers or associate editors as “award-quality” manuscripts during the review process. Award-quality papers, which typically represent less than 5% of papers published in a given year, are nominated for awards by associate editors, technical committees, or technical administrative committees. Final selection for an award is made by ASCE’s Honors and Awards Committee.

Awards for winning papers are handed out at the Structures Congress or the National Conference. This year, however, I would like to start a new tradition of recognizing and highlighting these outstanding papers and their authors in the pages of the Journal. It is interesting that two of this year’s winners (the Moisseiff and Reese awardees) are from a special section of a single issue (Vol. 134, No. 9) that focused on steel structures, specifically steel beam stability and strength.

The 2010 Collingwood Prize went to Professor Paul W. Richards of Brigham Young University. His paper, “Seismic Column Demands in Ductile Braced Frames” (Vol. 135, No. 1, pp. 33–41), focused on the seismic behavior of ductile braced frames, specifically on column demands during seismic events. The study addressed three types of systems: buckling-restrained braced frames (BRBFs), special concentrically braced frames (SCBFs), and eccentrically braced frames (EBFs). Different system configurations were also considered, including 3-, 9-, and 18-story systems. Using nonlinear time history analysis, Professor Richards showed that for columns at the base of 9- and 18-story BRBFs and EBFs, axial demands were 55–70% of demands commonly used in design. This is important because it points out areas for potential cost savings on columns, anchor rods, base plates, and foundations in tall buildings. In contrast, in low-rise SCBFs with braces in the 2-story X-configuration, column axial demands were considerably larger than those commonly used in design. The increase noted was up to 100% and was attributed to force redistribution that occurs after brace buckling. The study showed that column rotations in all frames were less than 0.03 rad, and it was noted that these rotation demands are lower than rotation capacities that were demonstrated in other works.

The 2010 Moisseiff Award was presented to Professor Joseph A. Yura (University of Texas–Austin), Professor Todd A. Helwig (University of Texas–Austin), Dr. Reagan S. Herman (John Hopkins University), and Dr. Chong Zhou (Technip USA). Their paper, “Global Lateral Buckling of I-Shaped Girder Systems” (Vol. 134, No. 9, pp. 1487–1494), focused on the lateral buckling behavior of I-shaped girder systems. While current design specifications consider only individual girder buckling between cross frames, the authors presented a new closed-form solution for the elastic global buckling of twin-girder systems interconnected with cross frames. The solution was presented in a form suitable for direct adoption into design specifications. Finite-element simulations were used to verify the closed-form solution and extend it to more practical loading conditions. Among the parameters investigated, it is shown that the load height condition had only a minor effect for twin girders, whereas it is well known that this effect is significantly more influential in single girders. Both singly and doubly symmetric sections were investigated in the study, and it was shown that girder spacing and the in-plane moment of inertia of the girders are the principal variables controlling global buckling of the twin-girder system. However, the number and size of the intermediate cross frames had little effect on the global buckling resistance of the twin-girder system. The paper also presented a full design example for improving global buckling capacity through the use of a partial top flange lateral bracing system.

Professor Donald W. White of Georgia Tech is the recipient of the 2010 Raymond C. Reese Research Prize. His seminal paper, “Unified Flexural Resistance Equations for Stability Design of Steel I-Section Members: Overview” (Vol. 134, No. 9, pp. 1405–1424), presented the fundamental logic and calculations behind the 2004 AASHTO and 2005 AISC provisions. The provisions in these documents for flexural design of steel I-section members had been revised in their entirety to simplify their logic, organization, and application, while also improving their accuracy and generality. While both sets of provisions for flexural resistances were fundamentally the same, the organization in AASHTO emphasizes design of typical welded I-girders, while AISC emphasizes design of noncomposite nonhybrid compact doubly-symmetric I-section members. The combined AISC-AASHTO rules were presented as a single set of flowcharts applicable for all types of steel I-section members. I would like to note that Professor White’s winning paper was actually one of a collection of five companion papers on the same general topic. These companion papers represented a distillation of the results of an ASCE/SEI Special Project that was conducted to develop an experimental basis for decisions made in the development of the 2004 AASHTO and 2005 AISC provisions for stability design of all types of steel I-section members.