Part 2

The American Society of Civil Engineers’ ASCE 7-22 load standard, Minimum Design Loads for Buildings and Other Structures, is now available, and substantive changes have been made to both the snow and rain provisions. This article is the second in a two-part series regarding these changes. Part 1 (STRUCTURE, January 2022) reviewed changes to the ground snow loads, which represents a shift away from uniform hazard to uniform risk, and the addition of a winter wind parameter to account for the variability in winter wind speeds on drift loads. This article reviews other revisions to the snow loads, including a more accurate estimation of the horizontal extent of windward drifts, revised thermal factors Ct to account for current trends in roof insulation and venting, and guidance on design loads for snow capture walls added to this edition. Also, changes were made to Chapter 8 to include a ponding head to the rain load, which provides a consistent approach to assess ponding.

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Humans have been building with biology for thousands of years. Dimensional lumber and mass timber are mature technologies based on materials produced using biological processes. Today, there is fertile ground for additional research and development of materials based on biological processes or biomimetic principles finding application in structural engineering. Advancements in biotechnology are giving rise to new biomaterials for construction that go beyond wood; bioinspired structures and biomimicry are potential tools to augment existing and entirely new structures. The term biomimicry is derived from the words bios and mimicry coming from the Greek language meaning life and imitation, respectively. The fundamental tenet of biomimicry is to mimic nature and leverage the biological principles that have resulted from evolutionary processes.

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Galloping Gertie, Part 2

The design evolution for the Tacoma Narrows Bridge (aka Galloping Gertie) was presented in the February 2022 issue of STRUCTURE. Soon after opening, the Tacoma Narrows Bridge exhibited significant vertical movements under various wind conditions. To address the issue, the owners and designers tried various modifications and were investigating additional steps to control or at least minimize the motions.

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If you are a practicing structural engineer, you have no doubt come across various forms of contracts outlining the terms of your agreements. These contracts may be with parties that engaged your services or from whom you sought services. You may have your own contract composed by your legal counsel. More likely, your contract is based on a template created by an organization that develops and periodically updates standard contracts. This article provides a brief overview of the types of contracts you may encounter and contract offerings available from several respected sources.

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Occasions may arise where parties collaborate on a project involving proprietary or otherwise sensitive information. To prevent that information from being misused, shared, and/or publicized, the parties often enter into a non-disclosure agreement (NDA). However, breaching an NDA can have serious consequences, even in cases of accidental misuse or disclosure. Below are some basic steps you can take to protect yourself and your company if you are working within the confines of an NDA. 

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The NCSEA Diversity in Structural Engineering Scholarship was established by the NCSEA Foundation to award students who have been traditionally underrepresented in structural engineering (including but not limited to Black/African Americans, Native/Indigenous Americans, Hispanics/Latinos, and other people of color). In 2021, four amazing students with bright futures in structural engineering received scholarships, and yet, there were many more deserving students that did not receive support.

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With 42% of bridges in the United States being over 50 years old and 7.5% of them labeled structurally deficient, it is time that scholars and practitioners take stock of the most recent developments in the fields of bridge asset management and maintenance, as a first step to improving America’s bridges. ASCE’s Special Collection brings together recent research on a number of key issues in these fields – such as bridge testing and inspection, climate change, and life cycle management – to help engineers and decision-makers make bridges safer. This collection is curated by Dan M. Frangopol, Dist.M.ASCE, Lehigh University, and Sriram Narasimhan, Ph.D., P.Eng (Ontario), M.ASCE, University of California, Los Angeles. Access at https://ascelibrary.org/bridge_asset_management.

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