High Wind Archives - Page 3 of 5 -

Educated in a FLASH, Part 1

Happy New Year! This week’s blog was written by Branch Engineer Randy Shackelford, P.E., who has been a guest speaker at numerous outside seminars and workshops as a connector and high wind expert.

As part of our mission to “help people build safer structures economically,” Simpson Strong-Tie works with many non-profit groups around the country, including the American Red Cross, Habitat for Humanity, and the National Storm Shelter Association. Another group we work with is FLASH, the Federal Alliance for Safe Homes.Continue Reading

Hurricane Sandy, One Year Later

[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.

Boardwalk under construction. Image credit: Matt Cross, Simpson Strong-Tie.

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.

Hurricane Sandy Rebuilding Strategy

I confess that I listen to a lot of pop music while driving to work, mostly because I forget to change the station after dropping the kids off. It can be slightly embarrassing if I drive with a coworker and I’m tuned into the “all Bieber, all day” station when I start the car.

On Monday, I was without kids and managed to hear several news stories on NPR about Hurricane Sandy. Transcript of one story is here and the NPR blog post about it is here.

The Hurricane Sandy Rebuilding Task Force released a report titled Hurricane Sandy Rebuilding Strategy. The report has 69 recommendations ranging from complex, such as setting minimum flood elevations that account for projected sea level rise, to relatively simple, such as states and localities adopting and enforcing the most current versions of the IBC® and IRC®.

The recommendations cover energy, infrastructure, sanitation, water, fuel supply, internet, transportation, and too many other things to list. But if I had to pick one word to summarize the report, it would be:

Resilience: The ability to prepare for and adapt to changing conditions and withstand and recover rapidly from disruptions.

Regardless of whether the natural disaster is high wind, earthquake, flood or fire, there has been a shift in public policy over the past decade to emphasize resilience. Resilience is a cycle. It begins with mitigation before the disaster. Some examples of mitigation that have appeared in this blog:

Seismic Retrofit of Unreinforced Masonry (URM) Buildings

Soft-Story Retrofits

Building a Storm Shelter to ICC-500 Design Requirements

Designing new buildings with specific performance targets is a form of mitigation as well. Resilience continues with response after the disaster, and then short and long-term recovery plans to reduce the time between disaster and recovery.

Have recent natural disasters such as Hurricane Sandy changed the way you are designing? Let us know by posting a comment.

– Paul

What are your thoughts? Visit the blog and leave a comment!

Steel Moment Frame Beam Bracing

In a previous blog post on soft-story retrofits, I briefly discussed beam bracing requirements for moment frames. This week, I wanted to go into more detail on the subject because it’s important to understand that a typical steel moment frame requires lateral beam bracing to develop its full moment capacity. Figure 1 below shows two common methods of beam bracing. While on the surface determining beam bracing requirements may not appear complicated, there are several items that could prove it to be more challenging than you might think, especially when steel moment frames are used in light frame construction.

Figure 1: Steel Beam Bracing

(A) Braced with kicker and metal deck(1)

(B) Braced with kicker and wood joist/beams(2)

Before going into beam bracing in steel moment frames, it is important to discuss the behavior of a simply supported beam under gravity load. Short beams (Lb < Lp)^[3], might not require bracing to achieve the full plastic moment of the beam section. However, when a beam is long (Lb > Lr) and without bracing, the beam can twist or buckle out-of-plane. Figure 2 illustrates these two behaviors along with the case where the beam length is somewhere in between the two (e.g., Inelastic lateral torsional buckling). In addition, if beam sections are non-compact, flange local buckling (FLB) or web local buckling can occur prior to reaching the beams full plastic moment.

Rebuilding with Simpson Strong-Tie Products After Hurricane Sandy

Our factory in Gallatin, TN held a Fastener Summit Meeting this past June, which brought together people from all areas of our fastener business. Somewhere, sometime we started calling these meetings “Summits” and the name stuck. The purpose of the Summit is to facilitate candid discussions about what we need to do to better support our customers’ needs through new product development, new application testing, literature, training, or sales distribution.

One of our fastener sales specialists shared a great story about a New Jersey town’s decision to build a better boardwalk following Superstorm Sandy. The town of Seaside Heights decided to design and build a boardwalk to better address future storms. Along with being a local icon, the boardwalk is an integral part of the town’s economy.

Working hand in hand with the town’s borough officials, the project’s engineering firm and contractor, our Columbus, OH branch worked to tirelessly to develop construction solutions to save time and money on this critical project. For Simpson Strong-Tie, this involved testing and ramping up production of stainless steel product to ensure no delays for the project.

A little over two months after Seaside Heights Mayor Bill Akers drove the first deck board screw using our Quik Drive auto-feed screw system, the boardwalk was complete. NBC’s Today Show broadcast live from the boardwalk with New Jersey Governor Chris Christie on May 24. There’s also a cool video on the New York Fox News website showing different time lapse views of the build here.

Seaside Heights Mayor Bill Akers drive in the first screw. — Seaside Heights Mayor Bill Akers drives in the first screw.

The Today Show airs live from the reconstructed boardwalk. — NBC’s Today Show airs live from the reconstructed boardwalk.

You can read the full story in the July issue of our Structural Report newsletter.

– Paul

What are your thoughts? Visit the blog and leave a comment!

What Did Sandy Teach Us?

In the weeks following Hurricane Sandy, I had an opportunity to visit some of the hardest hit communities in the region. At the time, many of New Jersey’s barrier islands were still completely closed off to civilian traffic and all accessible bridges were blocked by military guards. Our local territory manager has great relationships with building departments, so we were able to walk portions of Long Beach Island, NJ with an inspector. The storm surge washed out several sections of the protective sand dunes on the south end of the island in the neighborhood of Holgate and this is where we spent much of the day.

Scoured foundation temporarily shored. Holgate, NJ.

For a structural engineer, there was a lot to observe and many things I could write about here (maybe a future post), but what strikes me the most when looking back is the long- term impact this event will have on the region. The cost of Sandy goes beyond the loss of life and property (72 lives, $50 billion and growing). It would be difficult to estimate a dollar amount that accounts for the displacement of people and disruption to their lives, the hit to local economies that depend heavily on tourism, and the effect on the national economy and taxpayers; but I imagine it would be a staggering sum. So what, if anything, can structural engineers do about it?Continue Reading

Aren't We Done Testing Yet?

If you’ve been following the Structural Engineering Blog for any length of time, you’ve probably noticed that we like to run a lot of tests around here. Building test setups and breaking them is one of the things we enjoy the most in R&D at Simpson Strong-Tie, but often load rating a product is not as simple as just running a test. At times the process requires significant time and effort, so much so that we start asking ourselves, Aren’t we done testing yet?
We’ve posted on how we test connectors, holdowns, and screws. Most products have an ASTM standard or Acceptance Criteria that sort of tells you what to test. Yet figuring out how to test a product can be a challenge – in other words, how do we make sure our test simulates installed conditions? Or maybe a product can be used in so many different ways that it is unreasonable to test every possible installation, so what to do?
We have been challenged with these situations over the years, but probably never as much as with our connectors for curtain-wall construction that we introduced about two years ago. In particular, testing our bypass framing connectors to resist in-plane loads (designated as F1 loads) presented testing challenges.
Continue Reading

Aren’t We Done Testing Yet?

We’ve posted on how we test connectors, holdowns, and screws. Most products have an ASTM standard or Acceptance Criteria that sort of tells you what to test. Yet figuring out how to test a product can be a challenge – in other words, how do we make sure our test simulates installed conditions? Or maybe a product can be used in so many different ways that it is unreasonable to test every possible installation, so what to do?

We have been challenged with these situations over the years, but probably never as much as with our connectors for curtain-wall construction that we introduced about two years ago. In particular, testing our bypass framing connectors to resist in-plane loads (designated as F1 loads) presented testing challenges.

Storm Shelters in the Wake of the Oklahoma Tornado

As we continue to learn more about the devastation in Oklahoma from the EF-5 tornado that struck the city of Moore and surrounding areas on Monday, many building professionals and homeowners are questioning the safety of their homes and other structures in tornado-prone areas. Winds of the recent storm reached speeds up to 210 miles per hour and destroyed hundreds of homes, businesses, schools and hospitals. Many structures were leveled to their foundations. The question that is posed after an event like this is – can you build a tornado-resistant home or structure?

A recent article in the Huffington Post asked that question to several design professionals, including our own resident code expert, Randy Shackelford, P.E., a Simpson Strong-Tie engineer based in McKinney, Texas. While designing a tornado-proof home is not practical or economical, properly designed storm shelters can save lives. Take a look at the Huffington Post article here.

Last year, I wrote a post about Building a Storm Shelter to ICC-500 Design Requirements, which presents the most economical solution to resisting the strongest of tornadoes. We’ve also covered this topic from various angles in the blog, from design – a post about Code-Plus Programs that provides some guidelines for building structures that are more resistant to hazards than what the code requires, Designing Light-Frame Wood Structures for Resisting Tornadoes and checking for Building Drift – to addressing specific parts of a structure, such as Preventing Roof Tiles from Becoming Wind-Borne Debris and Roof Deck Design Considerations for High Wind Events. Our Technical Bulletin about how to strengthen dwellings in tornado-prone areas provides further information.

Our thoughts and prayers continue to be with everyone affected by the Oklahoma tornado. We are thankful to report that our local sales reps and families in that area are safe. If you have additional thoughts about the tornado and storm protection, please leave me a comment.

– Paul

What are your thoughts? Visit the blog and leave a comment!

Overview of Code-Plus Programs

We all know that the purpose of a building code is to provide minimum requirements for the health, safety, and welfare of the occupants of buildings built under that code. But what if the owner wants a building that will perform better than the absolute minimum allowed by the code?Continue Reading