While being located geographically in the middle of the United States, it may not seem like seismic bracing would be a major concern. After all, we don’t have the frequency of intense earthquake movement that covers news headlines like the west coast experiences.
Despite the (fortunately) absent frequency, the New Madrid fault line runs near Memphis, Tennessee up to the bootheel of Missouri.
[Note: Yes, we Missouri-folk actually describe a portion of the state as a “bootheel”. When you say it aloud, though, you have to add a little twang.]
Back to seismic – this fault line has the potential for very strong seismic activity just as much as portions of California and the Pacific Northwest. As a result, seismic bracing is common for us in southeastern Missouri, in St. Louis, and even into central Missouri and southwestern Illinois.
As we move away from the fault line, at some point, seismic movement would be less severe – even to the extent that bracing isn’t necessary.
Where is that point?
How do we determine when seismic bracing is necessary for fire suppression systems?
Today’s article is covering just that. It’s an exercise I practice commonly as I essentially live on the boundary of where seismic is and is not required by code.
International Building Code References ASCE 7
Seismic bracing has roots in NFPA 13. As is the case between a “code” and a “standard”, however, NFPA 13 as a standard only tells us how to design and install the system. Code tells us when and where systems and components are required.
The International Building Code Section 1613 for Earthquake Loads requires that “every structure… including nonstructural components that are permanently attached to structures and their supports… shall be designed and constructed to resist the effects of earthquake motions in accordance with ASCE 7”. [2015 Edition 1613.1]
There are a few exceptions, most notably detached one- and two-family dwellings in some areas.
ASCE 7 Requirements Based on Seismic Design Category
ASCE 7, Chapter 13 (2010 Edition), for Seismic Design Requirements for Nonstructural Components, states:
ASCE 7 Chapter 13 addresses Seismic Design Requirements for Non-Structural Components. Its scope covers the minimum design criteria for nonstructural components (like fire suppression systems) that are attached to the structure.
ASCE 7 Chapter 13 suggests that seismic bracing is required for all structures, unless they meet an exemption. Section 13.1.4 specifically lists exemptions from seismic design requirements.
These Exemptions include:
Additionally, ASCE 7 Section 11.7 states that Seismic Design Category A need only comply with Section 1.4 (not Chapter 13).
So What is a Seismic Design Category?
A Seismic Design Category is a “classification assigned to a structure based on its Risk Category and the severity of the design earthquake ground motion at the site.” (ASCE 7 Chapter 11 Definitions)
In short, it’s a classification on the entire structure, ranging from A (least risk) to F (greatest severity).
Seismic Design Category A structures encompass buildings of ordinary occupancy located on sites with stiff soils and have little risk of experiencing earthquakes.
Seismic Design Category F, on the contrary, are required to remain functional following a strong earthquake, such as hospitals and emergency communication centers, and are located very close to major active faults.
What Impacts Seismic Design Category?
Several contributing factors are combined to give the seismic design category. They principally include:
Structures that are of high importance following an earthquake, such as a hospital, are of greater importance and carry a higher risk category.
Soil conditions greatly impact the ability of the building to response to motion. Stiff soil or rock conditions generally allow the building to better respond to an earthquake. Loose, stiff soil, or soft clay don’t give buildings the ability to move with the ground, and therefore create worse seismic reaction forces within the building.
Lastly, and probably the most obvious, the building’s proximity to a major fault line. The closer to a fault line, the greater the seismic forces from an earthquake event for the same earthquake.
How to Determine Seismic Design Category?
The International Building Code Section 1613 allows the Seismic Design Category to be determined either by IBC 1613 or ASCE 7.
The International Building Code Section 1613 details the step-by-step process to determine the Seismic Design Category. This involves using data from site soil testing, the Risk Category, and earthquake severity parameters from provided maps.
ASCE 7 has similar provisions in Chapter 11, detailing similar inputs of Risk Category, Mapped Response Parameters, and site conditions.
In practice, however, there are third-party tools that help make this process much easier.
Here are a few available, for free online:
With the Risk Category, Address, and Site Information, a Seismic Design Category can be quickly determined for a building. These reports also give important design parameters that will be used for Seismic Calculations for the design of the system.
What if I Don’t Know The Site Class?
With new construction, structural foundation design requires geotechnical testing and reports which give these values. The structural engineer will assess the report, and typically place the building’s Seismic Design Category in their front-sheet notes or in structural specifications.
This isn’t the case with interior remodels or work within existing buildings. No soil testing is done and sometimes no structural work is done.
When this is the case, the International Building Code requires a Site Class D to be used (IBC 1613.3.2). This could be made more conservative by the building official if geotechnical data determines that Site Class E or F soils are present at the site.
So Does My Building Require Seismic Design?
Back to the original question – once we know the Seismic Design Category, it’s easy to determine where fire suppression systems require seismic design.
If the Seismic Design Category is A or B, then Seismic Design Criteria does not apply. If the Seismic Deign Category is C, D, E, or F – then Seismic Design Criteria applies. Under this later scenario, all the requirements of NFPA 13 for Seismic Design now become an enforceable requirement for the system design.
Here’s a summary of the code path:
Seismic Design Criteria for Fire Suppression Systems depends upon the Seismic Design Category for the Building. This Seismic Design Category incorporates the importance of the building, it’s proximity to seismic fault lines, and soil conditions at the site.
While the determination path through codes & standards might not be as clear as other system requirements, seismic design is nonetheless a crucial component for the performance of a fire suppression system and an important consideration in the design of the system.
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We love to poke fun at millennials. It’s like the holy grail of tradition.
“Kids coming out of school these days – you know? It’s ridiculous. They want twice the pay and half the work of when I came out of school. They don’t want to learn. They’re lazy. There’s not enough talent. There’s not enough interest. They don’t work hard.”
Ever heard that before? How about this one -
“Young people think they know everything, and are always quite sure about it.”
Yeah – that last quote wasn’t exactly about millennials – Aristotle wrote it in the 4th Century BC. Every young generation is clearly, obviously, unexplainably worse than the one before it. Right? I mean criticizing the next generation has been going on for all human existence. I’m sure cavemen used to scorn at how the young have no eagerness to strike rocks anymore…
Millennials are so… entitled.
Yeah – I wrote it. Entitled. The worst label of all. That E word.
Millennials are so entitled that they don’t even own their own issues; those are of course caused by Boomer parenting. [see the half a million search results for “millennial poor parenting” on Google].
I mean clearly millennials are like the worst young generation we’ve ever seen? Right?
Back Off Another Joe/Millennial Soapbox
OK. So maybe the problem isn’t that bad. Maybe I exaggerate a little. Maybe I write too much in the third person considering my age technically qualifies me as a millennial. And yes, maybe I do also blame my parents for all my nonsensical fears (thunderstorms and sinkholes, come on Mom!).
I was probably accused of being entitled a couple years into my post-college career. I felt good about the work I was doing, felt like I was understanding the curve, and I am sure it was showing in my attitude. A couple big project issues plus a bad annual review and I was quickly sized back to reality.
But entitlement doesn’t go away easily.
It was around that time that some coworkers went to a career fair at an area state college. One of the college students (a junior) inquired about the company. He got the normal pitch on working culture, opportunity, training and the whole bit. He then asked about management positions. After laughing it off my coworker realized the student was serious. He was looking for a management position as a quasi-21-year-old with zero real world experience!
After returning to work and sharing the disbelief, it’s easy to see entitlement in others when at that same time I probably couldn’t see it in myself.
I did get over it though. It wasn’t through shame or being a “company guy” or bad annual reviews. It was by starting my own side-hustle.
Takeaways from the Art Shop
I had always enjoyed creating sketches. During college I had a few architectural studio courses where we learned architectural sketching traditions. I enjoyed drawing and took some of those lessons to open a small art shop online.
That experience brought so many positive perspectives into my life.
It started with only one sale in the first two months of opening. It was a wonderful feeling. Then one good review led to another sale in month three. In month four I had two sales. Month five I doubled again.
With each touchpoint I worked on improving the customer experience. I learned quickly to be responsive to customers. I learned how to deal with unsatisfied customers – which meant putting frustrations aside and owning-up to every misstep. I learned how taxation is theft (ok not really – but it is a major downer).
Probably one of the most important things I learned from the basic art shop is that I had to take ownership of the work result. It never mattered how hard I tried to draw. If I created something that offered no value to others, it wouldn’t sell and had no value. That’s the real-world economy.
People pay for value. How was I to bring value to a customer? How could I improve the value I offered? How could my presentation and correspondence be improved to help convey value? I thought about all of those things, constantly.
That also began slowly translating to the workplace. Just because I put in effort – if the end result was incomplete, sloppy or just wrong – then I was not producing value.
The essence of entitlement is believing that showing up is enough. It’s not. The value we provide for the world is our all-in engagement with doing great work.
Employee vs. Ownership Perspective
Starting that art side-hustle slowly and fundamentally changed my perspective about business and serving people.
As I see it – there exists an Employee and an Ownership mentality. An Employee mentality asks – “why doesn’t our company pay for X?”, “they underpay everyone here”, “they never pay for good software”, and on and on.
The Ownership perspective is looking holistically at the business. “How can we better serve our clients?” “How can we improve work culture?” “How can we improve productivity?” An Ownership mentality links personal responsibility to their work and representing a brand.
I didn’t have to have a stake in a company to begin to develop that perspective. Businesses exist to make money. If businesses didn’t make money for a long period of time, then they fold and cease to exist. That’s reality, and that’s not a bad thing either.
But just adopting an Ownership perspective brings about a world of possibilities. Company limitations don't become obstructions - they just become a problem that needs a creative solution.
That art business grew, and grew and grew. Just three years in I sold over 600 pieces in a year. Wild. Especially for an ameateur artist who's dayjob is being and engineer. That shop still exists at www.etsy.com/shop/artbyjosephdalton. There’s not much time into it anymore now that the fire protection content is top priority – but I’m so thankful I started that shop because the lessons it taught has been invaluable.
Want to change your perspective? Start that side hustle you’ve always wanted. It just might unlock a fresh way of looking at the world.
Enjoy this article? Here are other career-related articles:
Being Deliberate About Your Future
Does Your Job Title Matter?
Knowledge is Not Just in Education
Fahrenheit 451 & The Thirst for Knowledge
Heartache of Failure in Life Safety Design
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Last week we explored when duct-detectors are required under the International Mechanical Code (IMC).
While the IMC is the most commonly-applied standard in the United States, it's not the only standard that dictates terms for duct detectors. Many international projects under NFPA 5000 or government facilities under Unified Facilities Criteria (UFC) pull in smoke detection requirements from NFPA 90A.
This week's post covers a cheatsheet for duct-detection requirements under NFPA 90A. Selfishly I've been wanting a quick go-to when covering fire alarm design, and now I'll have a copy for the two most common standards.
Around here we laminate cardstock color prints for these cheatsheets. If you'd be interested in purchasing a set of cheatsheets, let me know by commenting here. If there's enough interest I'll set up something in our store.
Thanks & have a great week!
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Joseph Meyer, PE, is a Fire Protection Engineer in St. Louis, Missouri. See bio on About page.