Throughout the ages, humanity has been warned – do not build on weak foundations. Even the “Good Book” uses a parable of a home built on sand to emphasize the importance of a solid foundation in life.
However, the wise sages of the past did not live in today’s fast-paced world. As hard as most members of today’s society try to be good stewards of the land, some things get pushed to the wayside… literally. …
Recent developments in prescriptive fire resistance design resulted in the introduction and advancement of UL Design D982. A principal advantage of this UL design is that it provides the same fire protection thickness requirements for 2-hour assembly ratings regardless of whether the classification is restrained or unrestrained. …
Demonstrating the need for utilizing finite element modeling (FEM) and analysis (FEA) to accurately model, analyze, and efficiently design masonry wall systems was the subject of a STRUCTURE article in May of 2016. Hopefully, the reader used the information in the article and is well on their way to building FEM that include structural masonry elements. With that background, they should be ready to advance their design of masonry with the aid of FEM. …
The author’s company, a forensic engineering and architecture firm, has investigated hundreds of low-slope roof and exterior deck applications with water stains, ponding, framing damage, and structural collapse. The first article, Part 1: ¼ in 12 Design Slope and Water Drainage (STRUCTURE, August 2017), examined two building code parameters that contribute to low-slope roof and deck serviceability issues. …
Construction Science and Engineering, Inc., an architectural and engineering firm, has investigated several low slope roof applications with water stains, ponding, framing damage on the lower side of the roof span, and structural collapse. Further examination typically reveals a relatively level surface when compared to other roof locations (Figure 1). A similar occurrence is often found in exterior deck applications. …
Structural engineers occupy a unique position in building design in that they are the sole resource for most of the information that is critical to the building cladding design. The Structural Engineer of Record (SEOR) is responsible for designing the lateral and gravity force resisting systems of buildings to perform within certain code prescribed seismic (and wind) drift limits. They also provide the design for roof and floor spandrel elements (for multi-story buildings) to perform within specific deflection criteria, based on the exterior cladding system and function. …
This article is the conclusion of a two-part series which discusses the seismic design provisions for nonbuilding structures found in Chapter 15 of ASCE 7-16, Minimum Design Loads and Associated Criteria for Buildings and Other Structures. The previous article (Part 1, STRUCTURE, April 2017) provided an introduction to the seismic design of nonbuilding structures. …
The title of ASCE 7-16 is Minimum Design Loads and Associated Criteria for Buildings and Other Structures. This article is the first in a series intended as an introduction to the seismic design of the “other structures,” commonly known as nonbuilding structures. …
The future of short span steel bridge design began in 2009 with a challenge from the Federal Highway Administration (FHWA). FHWA challenged the North American steel industry to develop a cost-effective short span steel bridge with modular components which could be placed into the mainstream and meet the needs of today’s bridge owners, including Accelerated Bridge Construction (ABC). The challenge was issued to help address the U.S. infrastructure crisis of structurally deficient and functionally obsolete bridges, nearly half of which fall in the short span category (defined as bridges under 140 feet). …
The previous two STRUCTURE magazine articles (General Principles of Fatigue and Fracture, Part 1, August 2016 and AISC and Damage Tolerance Approaches, Part 2, November 2016), reviewed the fundamental principles of cracking and how to design for fatigue and fracture. This article presents three case studies that illustrate how an engineer can use this guidance to address project challenges. The intent of this article is to move from the theoretical to the practical, and demonstrate that there is a realistic place for the more developed methodologies of fatigue and fracture mitigation. …