My blog post is late this week – I’m going to blame it on vacation. According to this article analyzing a study by Expedia, Americans did not use $34 billion worth of vacation time they were entitled to in 2011. This started me thinking about how difficult it can be for structural engineers to take a real vacation.Continue Reading
To launch our Structural Engineering Blog, in April we hosted a sweepstakes inviting you to sign up for blog email updates by June 1, 2012. Everyone who also posted a comment to the blog during that time period received a bonus entry into the sweepstakes. The five winning entries received a Simpson Strong-Tie prize pack. Congratulations to our winners:
R. Johnson – Chicago, Illinois
D. Bentti – Anchorage, Alaska
R. Porter – Westfield, MA
D. Weinstein, PE – Philadelphia, PA
Z. Andriuk – White Plains, MD
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The 2009 IBC Section 1604.4 states, “Load effects on structural members and their connections shall be determined by methods of structural analysis that take into account equilibrium, general stability, geometric compatibility and both short and long-term material properties.” This requirement applies to a 200 pound handrail connection as well as a 50,000 pound glulam connection.Continue Reading
According to the National Weather Service, 2011 ranked right up there as one of the worst years on record for tornadoes, having set records for the earliest date of the first tornado, the most states reporting tornadoes, the greatest monthly total, the greatest daily total, and the highest estimated property and crop losses. (Take a look.)
You may wonder: What can I do to protect building occupants (perhaps even my family) in a tornado? It is possible to build your home to higher wind resistance than normally required so that it can resist weak to moderate tornadoes? See my previous blog post, “Designing Light-Frame Wood Structures for Resisting Tornadoes. It Can Be Done!” and also our tornado technical bulletin for more information. But to resist the strongest of tornadoes, the most economical solution is a storm shelter located nearby or in your home. Continue Reading
Prior to joining Simpson Strong-Tie, my career involved the design of projects in California’s San Francisco Bay Area. When designing the primary lateral force resisting system, I would have several pages of seismic base shear calculations and, oh yeah, a one- or two-line calculation of the wind forces – just to show that seismic governed. There was no need for complete wind analysis, since the seismic design and detailing requirements were more restrictive. Of course, building components such as parapets, cladding or roof screens needed a wind design. Unfortunately, when wind appears to control, meeting the seismic requirements is not so simple.
Prior to the 1997 Uniform Building Code (UBC), there were limited code provisions for design of cold formed steel-framed shear walls. The 1994 UBC had seismic R-factors for light-framed walls, but little else with respect to design or detailing. Code provisions were introduced in the 1997 UBC that included:
A few years ago, we hosted a Take Our Daughters and Sons to Work® Day at our home office in Pleasanton, CA. During introductions, several parents told the children what they did and how they chose their particular profession (you can see what my son thinks I do in my bio). At our home office, we have accounting, finance, product management, IT, administration, marketing, and a few others I’m probably missing, so it is a diverse group the kids heard from that day.
And the careers were often not what people had originally planned for. Many shared wonderful stories about the twists and turns their careers took until they finally discovered their passion and job satisfaction. Often, this was a career that they didn’t even know existed when they chose a major in college or first entered the workforce.
So, what was my story?
I often get asked about Simpson Strong-Tie R&D projects. Since I can’t always talk about what new products we are working on, I thought I’d give you a sneak peek into where the magic happens. The Tye Gilb Research Laboratory is our R&D hub. Built in 2003 in Stockton, CA, the lab is named in memory of Tyrell (Tye) Gilb, a former professor of architecture and a wonderful man, who led our company’s research and development efforts for 35 years.
We structural engineers here at Simpson Strong-Tie have a love/hate relationship with anchorage to concrete. Ever since the introduction of the strength design provisions in the 2000 IBC and ACI 318 Appendix D, anchorage to concrete has been a challenge for designers, building officials and manufacturers. SEAONC’s recent testing and the resulting code changes offer some relief to wood-frame designers for sill-plate anchor design at the edge of concrete, but many challenges remain.
With the increasing demand for high-density housing and urban infill projects, designers are now faced with anchoring multi-story wood-framed shear walls to relatively thin elevated concrete slabs (typically referred to as podium slabs). Overturning tension anchorage forces at the ends of shear walls in these projects can routinely be in the 40 kip range and even get as high as 60 kips or more.
“One test result is worth one thousand expert opinions.”
– Wernher von Braun
While reviewing some of our first catalogs, I was curious about the testing we did on those iconic products that launched our company. I found a test report from December 20, 1957 on crinkled yellow paper with a short description: U-29 Download Test. The signature from the independent testing agency was a little faded, and the data was typed by hand in a table. But I was thrilled to discover that our 1957 customers received exactly the same thing as our modern-day customers – the confidence in knowing that our allowable loads are supported by physical testing.
There simply is no substitute for a physical test.