Welcome to our Structural Engineering Blog! I’m Paul McEntee, Engineering R&D Manager at Simpson Strong-Tie. We’ll cover a variety of structural engineering topics here that I hope interest you and help with your projects and work. Social media is “uncharted territory” for a lot of us (me included!), but we here at Simpson Strong-Tie think this is a good way to connect and even start useful discussions among our peers in a way that’s easy to use and doesn’t take up too much of your time. Continue reading
I attended a CFSEI and Steel Framing Alliance webinar last week entitled Specifying Cold-Formed Steel: Finding and Avoiding Pitfalls in Structural General Notes and Architectural Specifications. The presenter was Don Allen, PE, from DSi Engineering, LLC, and he focused on issues specifically related to design and specification of cold-formed steel (CFS) in contract documents.
The first post I ever wrote for this blog was But I Don’t Design Cold-Formed Steel… I talked about how limited my initial experience was with cold-formed steel and how I was forced to learn it on the job when projects required it. During the webinar, I winced a few times recalling my first CFS project when Don mentioned why you should not do certain things — and they were things I used to do.
Referencing the “most current edition” of a standard was something I remember doing in our general notes, and the webinar mentioned why it is important to verify that specified reference standards are correct for the governing building code for the project. I first designed under the 1994 Uniform Building Code, and then used the 1997 UBC for many years after that. The Uniform Building Code was almost self-contained in that it covered gravity, seismic, and wind load requirements in Chapter 16, and then each of the material chapters had most of the design requirements in the code.
A significant change in the International Building Codes has been removing many of the design requirements and simply referencing the appropriate design standards. Whereas the UBC had methods for calculating wind loads, the IBC simply refers you to ASCE 7 for wind loads. Similarly, Chapter 19 of the 1997 UBC had many pages of concrete design requirements. Now, the 2012 IBC has just a few pages referencing ACI 318 and then makes several amendments to it.
While the title of this blog post might remind you of the tasty turkey dinner you enjoyed on Thanksgiving, it’s actually a question regarding a shear wall component’s effect on performance. What type of fastener do you use to attach wood structural panel sheathing to cold-formed steel (CFS) framing, and what is the effect on a shear wall assembly?
Structural sheathing is most commonly attached to CFS framing with self-piercing or self-drilling tapping screws, power driven pins, and adhesives.
The AISI North American Standard for Cold-Formed Steel Framing – Lateral Design standard (S213) specifies using either #8 or #10 self-tapping screws (depending on the assembly) that comply with ASTM C1513, and have a minimum head diameter of 0.285” or 0.333”, respectively.
It’s worth noting that you cannot verify ASTM C1513 compliance by simple inspection. While screw dimensions are easy to measure, other features such as hardness, ductility, torsional strength, drill drive, and thread tapping cannot be evaluated in the field or by visual inspection. It’s prudent that a Designer and jurisdiction expect a screw manufacturer to validate its product’s compliance with ASTM C1513. This can be done through test reports by an accredited test lab and evaluation data, or by an evaluation report published by an ANSI-accredited product certification entity such as ICC-ES or IAPMO UES. Continue reading
What are your thoughts? Visit the blog and leave a comment!
The Wei-Wen Yu Center for Cold-Formed Steel Structures has issued a Call for Papers for the 22nd International Conference on Cold-Formed Steel (CFS) Structures, to be held Nov. 5-6 in St. Louis, MO. The goal of the conference is to enable sharing of state-of-the-art information pertaining to CFS design.
Both engineering researchers and practitioners have provided valuable contributions to the conference. Past proceedings are available online.
Researchers and practitioners are encouraged to submit abstracts for consideration by the conference steering committee. Application-oriented topics highlighting innovations in CFS applications are strongly encouraged. The deadline is Dec. 31. Abstracts may be submitted by e-mail to firstname.lastname@example.org.
What are your thoughts? Visit the blog and leave a comment!
NOVA, the highest rated science series on television, recently aired a segment on the Colorado State University-led NEES-Soft project that tested Simpson Strong-Tie® Strong Frame® special moment frames as a seismic retrofit solution for soft-story buildings. Simpson Strong-Tie and our special moment frame were prominently featured in the clip. You can watch the entire “Making Stuff Safer” episode on PBS here.
A couple of years ago, my brother-in-law asked if I could stop by the swim club where he is a board member. He was overseeing a construction project to upgrade the buildings and patio covers, which involved dry-rot repairs and the addition of Simpson Strong-Tie® connectors to create a continuous load path. He wanted me to meet with the contractor and make some suggestions for alternate connectors. The as-built conditions didn’t work for the specified connectors at a few locations, and there were some spots where he thought the connectors were “ugly.” I’m probably in the minority on this, but I think shiny galvanized steel connectors are just beautiful. So the “ugly” comment stung a little bit.
Once I got over my hurt feelings, I grabbed my Wood Construction Connectors catalog, a Deck Connection and Fastening Guide, and a few other fliers and technical bulletins that I thought might be helpful and drove across town to meet them. With literature in hand, we were able to come up with ways to work around the more difficult areas, and also select some more aesthetically pleasing architectural connectors at prominent locations. I thought we were done, and then the contractor had a few more questions on anchoring that I needed an Anchoring and Fastening Systems Catalog to look up some information on – and I didn’t have one! I managed to muddle through with my smartphone and find the information online, but couldn’t help but think that there had to be a better way to access design information when you are out of the office.
The better way has arrived in the latest version of the Simpson Strong-Tie® Literature Library mobile app. It was just launched this month and is much more comprehensive than the first version. There are several new features that I wanted to highlight for you.
This week’s post comes from Bryan Wert,one of our engineers at the Simpson Strong-Tie McKinney, TX branch. Bryan provides technical product support, new product R&D, and customer education/training for the Southeast U.S. territory. Before starting his career with Simpson Strong-Tie early in 2007, he worked as a structural engineer at a large consulting firm in Las Vegas, NV. Bryan’s design experience ranges from single-family tract and custom homes, to retail centers, to hotel and condo projects. Bryan graduated from USC with a B.S. in Civil Engineering (Building Science emphasis) and from Stanford University with a M.S. in Civil Engineering (Structural emphasis). Here is Bryan’s post:
My wife, Kristin, sometimes gets angry with me while grocery shopping. It’s understandable. She’s asked me to grab some tomatoes or a loaf of bread and instead I’m just standing there looking up at the ceiling. Technically, it’s not a ceiling, but the underside of the roof, and I’m looking up to see the connection detailing, including whether or not the steel roof deck I’m looking at was welded, pinned, or screwed down to the steel joist, beam and angle supports.
If you’re a structural engineer, you might also do this inside your local supermarket, Target, Walmart or The Home Depot. Many of these “big box” stores are typically constructed of tilt-up concrete perimeter walls, tube steel interior columns, and roofs built of steel joists, girders and decking. Though Simpson Strong-Tie is well known in the light-frame wood construction industry, some may not know that we’ve long been developing and selling anchors and fasteners for commercial construction.
Outside of a few dips into a Verco or ASC steel decking catalog from my consulting days in Las Vegas, my first real foray into the steel decking industry was about two years ago. I was asked to assist in representing Simpson Strong-Tie as an associate member at the Steel Deck Institute’s (SDI) quarterly meeting held just down the road in Dallas in November 2011. Since joining SDI, my main focus has been to find out what the industry needs, both from the installer’s and designer’s standpoint for steel deck attachment. Though we’ve had a screw attachment offering for years, my colleagues and I have worked to develop a better overall system which now includes:
The Structural Engineers Association of Northern and Southern California hosted the third annual Buildings At Risk ǀ Earthquake Loss Reduction Summit in Los Angeles on October 8 and in San Francisco on October 15. Robust panel presentations and discussions presented by professionals from diverse yet complimentary fields targeted a mixed audience of building owners, architects, engineers, government officials, insurance representatives, and financial industry representatives.
The first panel, The Single Building and the City: Why Every Building Counts, discussed community vulnerability due to our increasing interconnectivity and how the demise of certain individual buildings from a seismic event could have large detrimental affects on the initial response and recovery of the city or the region they’re located within. Buildings which house important or widely used computer networks and servers or the major employer of a community are just a few examples.
[Simpson Strong-Tie note: Shane Vilasineekul is the Simpson Strong-Tie Engineering Manager for the Northeast U.S. and one of our guest bloggers for the Structural Engineering Blog. For more on Shane, see his bio here.]
The end of this month will mark the one year anniversary of Superstorm Sandy hitting the coastlines of New Jersey, New York, and surrounding states. A lot of construction has taken place in the last 12 months, but most of the rebuilding will occur over the next few years. The boardwalks were a high priority because of their effect on tourism, which is so vital to the local economies, and most of them have been completed (see my previous post about rebuilding after Sandy here). Now the focus has shifted to repairing, raising, and rebuilding homes.
I am writing this while sitting in the Newark airport, headed home after presenting one of our workshops on high wind design. The workshop was held at a hotel in Manahawkin, New Jersey that happened to be used last year by residents displaced by the storm, including some of the architects and engineers in attendance this morning. After talking to a few of them at the breaks, it sounded like they are struggling with the current state of building provisions, which were quickly put in place to ensure rebuilt properties are more resilient, including new flood elevations and renewed focus on code compliance.
I attended the SEAOC Convention in Santa Fe last year, and briefly mentioned it in this blog post. It was the first convention I had attended. I knew the presentations would be top notch based on the topics and knowing many of the speakers, but I had no idea how much Ashraf Habibullah and the other folks at Computers and Structures loved to party! The event they hosted at the Gerald Peters Gallery was beyond anything I expected – amazing food, art, dancing, open bar and even iPad giveaways.I was looking forward to attending the SEAOC Convention in San Diego this year, until I realized I would be in Quebec for ASTM D07 committee meetings that week.
So this week’s post summarizing the SEAOC Convention comes from Tim Stauffer, an R&D Engineer at our headquarters. Since joining Simpson Strong-Tie in 2008, Tim has worked on lateral system products, product development for our wood connectors, and development of products for the cold-formed steel industry where he was lead engineer for development of our line of connectors for curtain-wall construction. Prior to joining Simpson Strong-Tie, Tim worked for 15 years as a consulting structural engineer, including eight years where he ran his own practice. His experience includes the design, analysis and investigation of steel, concrete, masonry, and wood-frame buildings. Tim is a licensed professional engineer and structural engineer in the state of California. He received his bachelor’s degree in Architectural Engineering from Pennsylvania State University, and a Master’s of Science in Civil Engineering from UC Berkeley.
What do structural engineering, reconnecting with old friends, Shamu the whale, and a restaurant that serves the biggest calzone around have in common? The 2013 SEAOC Convention, of course! Held September 18-21 in San Diego, the annual convention is a great opportunity to learn about advances in the structural engineering profession, as well as spend time networking and re-connecting. Simpson Strong-Tie has always been a SEAOC supporter, and this year was no exception with a number of us from headquarters attending, as well as engineers and sales folks from our two California branches.
The two-and-a-half days of technical sessions included presentations on sustainability and design for solar installations; advancements in design for wood, concrete, and steel; wind, seismic, and blast analysis and design; tall structures and base isolation; and presentations on a variety of unique design projects. Of particular interest to many of us at Simpson Strong-Tie were presentations on high-rise wood structures, the growing use of cross laminated timber (CLT), the NEES-Soft testing performed at UCSD (including tests of buildings strengthened with our new Strong Frame® special moment frame), and advancements in steel moment frame design. Go here to view the convention program, including a complete list of the technical presentations.
In addition to the top-notch technical sessions, there was plenty of opportunity to reconnect with colleagues and build new relationships. Many of us worked for consulting firms before coming to Simpson Strong-Tie, and the convention was a great opportunity to catch up with former co-workers. The ability to maintain connections with designers is invaluable for us as we develop products to solve real-world challenges to help people build safer, stronger structures. For more about the value of networking and how to get involved with industry organizations, see Annie Kao’s recent blog post.