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Oct. 5, 2021

021 - Resilient design for firefighter safety with Ali Ashrafi

021 - Resilient design for firefighter safety with Ali Ashrafi

It is hard for us, fire safety engineers, to talk to firefighters on how to do their job... Probably we even shouldn't, as we have no idea how it is to truly go there into the heat and battle fire to save lives. But it does not mean we should not care. Firefighters are important actors in the fire safe world, and we cannot design buildings as if they were not. In the end, the probability of you being in a fire is fairly low, while for a firefighter this P = 1. Our decisions shape the building environment, which acts as a battleground for them, affects their actions and options. And we can design buildings better!

My today's guest, dr Ali Ashrafi of Thornton Tomasetti is passionate about building safer buildings. Ali highlights the key elements of making the building safer for firefighters, with a great focus on the structural resilience of the buildings. Highlighting the performance-based design approach he claims that we can build not only better but also cheaper at the same time. Well, that's kind of a win-win situation... If you want to learn more, this episode is for you.

Learn more about Ali at:
https://www.thorntontomasetti.com/person/ali-ashrafi

And connect with him through LinkedIn

Followup material:

 

Transcript

Wojciech Wegrzynski:

Hello, and welcome to Fire Science Show Episode 21. Great to have you here. As always, before we jump to the episode, I have some housekeeping items. I recently observed a spike of new listeners to the podcast with them, recent episodes. And I welcome you all. I hope you have a great experience staying with the fire science show. On the site .Of. .The .Fire science, the firescienceshow.com. I've started up selecting the episodes to assert them themes of the podcast. So that allows you explore and experience the podcast in a more organized way. And if you just joined us now, there's 20 great episodes waiting for you to be discovered. So I hope that's a great experience for you, and I hope you. Enjoy that I would also like to thank everyone who's supporting the podcast through the donations to buy me coffee on my webpage. I really appreciate this donations. They allow me to maintain the high quality of the podcast and pay for all the technical aspects of doing this in an slightly easier way. I appreciate your donations and, yeah, it helps me more than you think. Thank you so much. So for the episode today, Last week, I've hosted professor Brian Meacham, who said so much profound things about the shape of fire safety engineering, and how can we build it better together. It was a great episode and a fantastic discussion for myself today. I have an engine. Who's actually putting this things into motion. He's someone who's dealt with wind engineering, earthquake engineering, fire engineering, and has a head full of ideas. How we turn the buildings we design slightly better environment for firefighters. And the topic of today's episode is firefighter resiliency or buildings, resilience for firefighting. And my guest is Ali Ashrafi, he is with, , Thornton Tomasetti company, but also lined with a Colombia University where he is lecturing, wind, and earthquake engineering for 10 years. And recently has started structural fire engineering course, and Ihope it's going great. Ali has some great thoughts on how the design influences the battleground the firefighters will be fighting on. How can we think about the design in a way that promotes easier firefighting or safer firefighting and how it all aligns into the performance-based engineering framework. So, If you've enjoyed the episode with Brad Mitchum, you will enjoy this one for sure. Because it's like, the actions that we need to take, to fulfill Brian's prophecies. And if you haven't heard that episode of the Brian who shoots, but I'm sure you will like this one as well. So, let's not prolong this. That's welcome Malia roughy and these episodes. So yeah, that's been Dane shore and jump into the episode.

wojciech_wegrzynski-2021-9-14__20-4-19:

Hello everybody. I'm here

Wojciech Wegrzynski:

today with Ali Ashrafi who is with Thornton Tomasetti. Hello Ali, good to have you here

Ali Ashrafi:

Hi Wojciech, thank you for having me.

wojciech_wegrzynski-2021-9-14__20-4-19:

Really happy to have you here. And today we're discussing a very important subject of a structure, fire engineering, the firefighter resiliency in the buildings we design. But as you are a fire engineer who is located in the New York, we are three years after the 20 year

Wojciech Wegrzynski:

anniversary of 9/11. From

wojciech_wegrzynski-2021-9-14__20-4-19:

your view, like you're in the big apple, how did, this tragedy change the world of structural fire engineering and maybe structural fire engineering from your perspective?

Ali Ashrafi:

First of all, thank you for having me here. And to some extent, the timing off it was a coincidence that we are at the 20th anniversary, but it does bring up a lot of the discussions and the events of that day and the collapse of the buildings. Instructive in things that are similar, but things that are also different, obviously those events were unique. It was, we had collapses that were a result of many things, starting with massive planes, hitting buildings and taking a big part of this structure out and taking the fireproofing out and then a massive fire on multiple floors going with no response. So in some ways that's very different from any other building that we designed for. That's something to highlight that in any standard design that we're looking at, even more resilient designs, we're never designing for that level of damage to a building. Having said that you look at what happened and there are certainly lessons learned. First of all, those buildings actually, Pretty resilient. A lot of people got out of those buildings in spite of the massive damage to the buildings. And that highlights the role of structural stability and resilience of a building that can take some level of damage. And then even in a typical case, that would be a massive fire in a building. Right. You might have a fire that starts in your sprinklers. They don't control it and it grows. And now you have something massive acting on your building. It highlights the importance of that resilience. Certainly. It does highlight the importance of how the different pieces of design have to work together. So it was the building that stood for some duration. It was also, people were able to evacuate the building in that time period. When you look at what happened, almost anyone that was below the floors, where there was the impact they got out. It was the people who were above and that they basically lost their means of egress. It's those people who unfortunately could.

wojciech_wegrzynski-2021-9-14__20-4-19:

And the ones who, who came into the building game

Ali Ashrafi:

Absolutely. And that's where the firefighter safety issue comes in. And it, again, highlights challenge that we designed this building and the ultimate goal. The first goal is life safety. And when you look at the life safety it's occupants and it's firefighters and occupants of a building, you want to get, have them get out. The chances of someone being in a building, with a massive fire in their lifetime is not very large. We're designing to minimize the risk of that to people, but any individual the risk that they're exposed to is small in their life. But if you're a firefighter that is your job, and that's something that you want to do for 20, 25, 30 years and do it day in, day out, go do your job, save people's lives, but also go back home to your family and be safe and not be, physically damaged in this process. Right. So when you're talking about safety, the people who are most effected and we should be really thinking about is firefighters who do go into these buildings at the worst time every day.

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It's difficult

Wojciech Wegrzynski:

to frame 9/11 as a success story,

wojciech_wegrzynski-2021-9-14__20-4-19:

there is something to that . The buildings could have collapsed much sooner killing all of them who were below the impact point for example. And it could have been a much bigger tragedy. I don't know if you

Wojciech Wegrzynski:

can like weight the tragedies,

wojciech_wegrzynski-2021-9-14__20-4-19:

just how big there are, but it was a huge strategy, but it could have one different, it could have taken a lot more lives. And, in this way, this structural resiliency, like the building survived for as long as it could. It's interesting to learn how buildings survive and what makes them survive that long. And how can we make it survive to meet our objectives? And this is something I really wanted to touch in this episode. In this podcast, I had some really cool interviews and between me and my

Wojciech Wegrzynski:

audience, and You are the

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only one who's not going to hear them because

Wojciech Wegrzynski:

this is theepisodes that are going to air

wojciech_wegrzynski-2021-9-14__20-4-19:

before your episodes. So you're in the most unfortunate position here, but I'm going to tell you what there were about. I've interviewed Danny

Wojciech Wegrzynski:

Hopkin from OFR consultants

wojciech_wegrzynski-2021-9-14__20-4-19:

who mentioned with whom we discussed mass timber and fire engineer, timber and

Wojciech Wegrzynski:

fire. And Danny he brought

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up the issue of objectives. Like fire resistance is horrible objective because for a small building, it means something completely different than for a tall building. I

Wojciech Wegrzynski:

had Brian Meacham who told

wojciech_wegrzynski-2021-9-14__20-4-19:

a lot about, this fire safety being a social technical, system of multiple things that have to align together. And again, the missing link in the system. Are the objectives in a way that start building a new world with better performance based engineering and better engineering. Overall first, we should be clear on what the objectives are, because if your objective is to have 60 minutes fire resistance on your columns, that's not a great objective after all. It's a compliance goal, not an objective. When we've connected, you told about this firefighter resiliency and for me, wow, that's an objective that we don't really often consider. We focus on egress. We focus on survivability of the structure long enough to not create this enormous harm. But as you mentioned, there are people whose job is to go

Wojciech Wegrzynski:

into such buildings. And in many

wojciech_wegrzynski-2021-9-14__20-4-19:

countries it's handled in different ways. And I wondered how in your view, we could, implement this objective of firefighter resiliency or the ability of the buildings to be firefighting as I understand it into the design process, because for me today, it's not there for.

Ali Ashrafi:

I agree with you. And, I do look forward to listening to these interviews when they air out. But you mentioned a couple of really key points. One of the most important things is a design should have an objective. And when you look at how we design for different risks, sometimes we're more explicit about that. Objective. Sometimes we are less explicit, by training I'm a structural engineer and when I'm looking at fire, that's where my expertise lies. But one thing that is really key here. These are complex multifaceted issues. And so no matter where each of us is coming from what the discipline is, we should be designing in the context of overall safety goals. And so there should be dialogue between these designs. These are not individual pieces of design, they should talk to each other. And the way that most designs are today, that doesn't happen.

wojciech_wegrzynski-2021-9-14__20-4-19:

Yeah,

Ali Ashrafi:

I want to add that when it comes to safety of destructure in fire, what we do right today, the common practice, which is a prescriptive practice. And you mentioned it's based on the fire resistance terminology is really not explicit. So in a fire resistance terminology, you take specific pieces of a building and you put them in a furnace for some duration and you say itpassed and thats great. But that actually doesn't tell you anything about how the building as a system is going to respond to the fire. And if I want to bring it back to the question of firefighters safety, I see really three things that are key and they should speak to each other. One of them is stability of the building. The building is the battlefield where you're fighting a fire. If someone's going in, they need to make sure that the building will not collapse in them. That is the baseline, right? So the structural stability is a really important piece. The second piece is evacuation, right? So we're doing all of this because we want to save lives. You want to make sure that A either you can evacuate everyone from the building safe. That includes after everyone comes out, that includes firefighters being able to do their job and coming out. Or if you're designed requires you to, have some people in the building or if the building is, think of a really high-rise building and things of that complex space, or think of a place where, you have people who are sick, who are disabled, who cannot evacuate easily. And so you, your design has to be, you really allow them to. Stay somewhere safe in a building until the fire is dealt with. That's that second question. The question of evacuation, and then the third piece of this is firefighting and firefighting needs things. There's an infrastructure in a building. If you look at again, a large complex building, there's a limit to what you can do from outside. Firefighters really have to come in. They need to get to where they need to get to. And that could be tens of floors up. They might need specific elevator access. They're competing for the stairs with people who want to get out of the building. And then they're relying on the building system regarding standpipes or availability of sprinklers to help them fight the fire. Those three pieces are all relevant and. They should speak to each other. They have an impact on each other. So for example, if you know that the building will survive the fire, and even if you don't do anything to building will not collapse on you, that might allow you to design the building in a way that people move from somewhere to a safe place in the building. It's a better, easier evacuation problem. It allows the firefighters to do their job much more safety at focused the effect, the effort more on firefighting. Whereas if you have a building where you have this risk of a building collapsing and people are inside the building, it's forces, the firefighters who take more risk, they have to make decisions that, ideally, they don't want to make, they wouldn't want to make, but they have to put their lives at risk because there are other lives at risk. Right. And so these things have to really speak to each other as part of this.

wojciech_wegrzynski-2021-9-14__20-4-19:

You said the firefighters can risk their lives entering the building. And you said that the firefighters would have to enter the building, but this is also an objective. If the building is supposed to survive, is it supposed to survive and be refurbished immediately to allow operation immediately after the fire, or we just want everyone out of the building and just whatever the final outcome of the fire is, it is what it is. And these are like three objectives. You can design a building to

Wojciech Wegrzynski:

survive the fire unscattered, you can

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have a building that,

Wojciech Wegrzynski:

will require refurbrishment, but it's reusable. And

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then you have, a building in which the safety is determined by the ability of everyone to not die in it while having a fire. If you are let's say a worker in the building this objectives are not that interesting for you. Mostly interested in saving your life from the fire. If you are the owner of the building. It's probably affected by the technical complexity of the building operations that are being held with that the business impact, the destruction of the building will have on your operations and the insurance you signed up for. So these are the things that will determine if you are okay with the building being burned to the ground

Wojciech Wegrzynski:

and you'll erect a new

wojciech_wegrzynski-2021-9-14__20-4-19:

one, or you will really need one to saved. But if you're a firefighter. I mean, that's a tough choice, you know? Should I go and save the building for the sake of a saving a building or more? Should I just, minimize the collateral damage around it? Obviously when there is a life at risk, it's a completely different topic because from my experience with firefighters, they will always go in to save lives. Because the guys are heroes, but from just the built environment perspective, I, I'm not sure if the objective of saving the building at any cost is,

Wojciech Wegrzynski:

is a feasible one. And

wojciech_wegrzynski-2021-9-14__20-4-19:

now let's go back to the design phase. How big changes in the design has to be made to, allow for these objectives to be done, like how much. Fire suppression, fire protection. I have to put in my building to go from just everyone out. And everyone's safe into the building is unscattered after the fire

Ali Ashrafi:

a couple of really good questions that you raised. So I'll try to address,

wojciech_wegrzynski-2021-9-14__20-4-19:

We can break them,

Ali Ashrafi:

both one at a time.

wojciech_wegrzynski-2021-9-14__20-4-19:

Yeah.

Ali Ashrafi:

You're absolutely right. The objective of the design really does depend on what you're designing for and what's the context and I'll give you the range and there's no one answer that the point of the design is the design should be appropriate for your building and its environment. So on one enough, let's think of a smaller residential buildings in a suburb. You have a two story, building. The risk of a collapse of the building. Once people come out is it doesn't have any other impact, broad, broader than that building in that case, most of the codes, really the provisions are there to make sure that people can get out safety, right? The building might burn out. You could build the building off combustible materials. There is no expectation because the consequences are manageable. The other end of the spectrumThink off... I'm in New York. So I'm going to use New York as the baseline, but you're in this dense urban area. And let's say you have a building that's large enough, substantial enough. You have a building to the right and the building to the left and subway in front of your building. Even if you get everyone out of the building is the collapse of this building at the end of that process, unacceptable goals. Probably not, but the codes today do not get you there. The codes do not explicitly design, which is a problem. Like when it comes to fire, they're designed for safety is all implicit. Nothing is explicit. There that's one of the problems. But back to your point, you have a range from in one end, you can easily get people out and the building might fall down and that's okay. On the other end, you have to be able to get people out. And even if that's the case, really, you don't want something to collapse because you are in a place where the damage is not contained. So that's the conversation that's relevant for each design, but also it does impact the regulations. So if you're building in New York, the requirements on new are tougher than if you're building in a suburb, and rightfully so because the consequences are more That's that point of it and then there are places where something in between might make sense, right? There are places where. It might be challenging, but you could design and you can get people out. And once people are out, then yes, a partial collapse or something where you have to refurbish later, that's an acceptable solution. So we don't want to say which one it is. It depends on the context. Now, going back to what it takes to design a building, such that, it can really survive and fire. And here I'm talking about. More substantial structures. I'm not talking about a two story residential light with building, right? I'm talking about more substantial buildings. It's doable and it's actually not extremely challenging. And if you do it right, a lot of times it's actually coming with cost savings. And the reason for that is the current approach to safety and fire. Prescriptive. And so you're doing stuff and you're hoping for safety, but you're doing it without an analysis. And for that process to work, you have to be really conservative in some parts of that process. Whereas in a design where you're explicitly designing for safety, Your goal is very clear, but you do things that's really helped you get there. You don't waste your resources in places where you do something and it's really not providing any impact. And so in a lot of these scenarios, you might be able to actually reduce your costs. Not because you're doing less, you're doing stuff smarter. You're actually designing as opposed to doing some general thing and hoping that it's going to be safe. And this is something that we see in other contexts, for example, for seismic risk. There's also a simpler way of designing and there is performance-based design and in which you really go through a lot more detail to design the building, looking at its actual behavior and the type of damage that you're going to get. And what we see there is we spent a lot more thought and effort in the design, but the designs typically end up being more resilient and cheaper because you're doing a smart design. So it's not about cost per se. It's that? No one designs it that way today for fire or for most of the buildings.

wojciech_wegrzynski-2021-9-14__20-4-19:

Okay. I'm gonna ask you a question that is in principle. Impossible to be answered. So who should decide, if we should pursue this particular objective because we're in this, I think loophole. If it is the firefighters to decide if they want to have the buildings, a bunker or just something that people can escape with. They, I believe they may not have the required amount of knowledge in terms of structural fire engineering or structural engineering overall to truly judge. If, one design is superior to another, it's very difficult. And in the end, this flattens the discussion to probably the fire resistance periods, because this is the easiest way to, proxy the fire resistance. If it's the fire experts like me or you, we don't know the firefighters craft, we learn from them. We talk to them, you are, maybe you have been, but. I've never been in a situation where I was fighting for my life, holding a hose in my hand and praying that the fire goes off. I've never been in such a situation. So I don't really know what is the mindset of a person fighting for their life and trying to save the life of another person in the building that is due to collapse. So I don't also think we are competent to say, okay, this is the objective we should go for because maybe in this way, we. Unintendedly forced the firefighters to enter a building because we say, okay, the objective was that the building will survive anything. So it creates, uh, if they trust us as a fire expert, as they

Wojciech Wegrzynski:

might think okay, super safe

wojciech_wegrzynski-2021-9-14__20-4-19:

and so on. And that, that might not be the case because we are unable to,

Wojciech Wegrzynski:

see all the fires.

wojciech_wegrzynski-2021-9-14__20-4-19:

And if you're just an authority, if you're a

Wojciech Wegrzynski:

person who, whowrites the law. You are neither

wojciech_wegrzynski-2021-9-14__20-4-19:

a firefighter nor fire engineer. In many places, you will be one of them. And I congratulate these places, but in most cases you are neither of them. You're a politician or something. And then all your knowledge comes from the advisers. And, this can lean to one side to another side and it's very difficult. How we get to this, thought out objective of which buildings are due to stand, which buildings are due to fail, which buildings

Wojciech Wegrzynski:

are just allow people

wojciech_wegrzynski-2021-9-14__20-4-19:

to escape and how we implement this risk levels in a way. We're in the

Wojciech Wegrzynski:

objective area. If the objective

wojciech_wegrzynski-2021-9-14__20-4-19:

is, not sharp, not really clear. How do you design right.

Ali Ashrafi:

Okay. I love the questions. That again, you raised multiple good questions. I'll try to answer from different perspectives. Design is never done in a vacuum. Right. So when we come to do the design, it is within a specific jurisdiction and there are codes and standards and there's a reason for that. When you look at the process of how those codes and guidances are put together, you see all these stakeholders coming to the table and having the discussion, because that should happen. That's absolutely right. Each of these stakeholders has this perspective that's relevant and valuable. And it's important to have those dialogues so that they are explicit about that. And for fire, just having the question is very important. What, one of the things I'm hoping to highlight as no one asks that question of what the objective is, right? You are doing certain things in the code and there's a presumption of the level of safety. And certainly there's a level of. Certainly for the more common buildings. But the question is when you're looking at these events that might be rare, but really high impact, what is the right way of dealing with them? So I think that's important to keep in mind. And then I'm going to give you two examples of where the process has worked well, or we have good examples. One is, several years ago, a lot of collaborative work that was included, NIST included UL and clip a lot of fire departments. I know New York was involved. Chicago Fire Department was involved. They did a lot of testing. And the goal here was to bring the fire science into the firefighting process and see if the firefighting tactics could be improved in a way that allowed for better, safer firefighting. So it's better for. Potential victims for occupy for occupants of a building and for the firefighters and that collaborative process resulted in improvements in how people fight fires today. And that's the good mother. These discussions need to have everyone in them. Bringing this discussion closer to the question of performance of buildings in the fire. We do have standards that speak to that. So for example, in, in the U S uh, ASC7, which is American Society of Civil Engineers, it's a document that talks about loading on buildings. There's an appendix E that's explicitly talks about performance space designed for structures for fire, and it talks about the objective and. At a bare minimum, there is people have to be able to evacuate the building safety with a lot of, safety factor on that. And then they might, and then you can have improved performance objectives where the building survives a fire, for example,

wojciech_wegrzynski-2021-9-14__20-4-19:

And who decides, if you go into

Ali Ashrafi:

The process always needs an approval. So you would have the authority having jurisdiction. So it could be a building department. Sometimes it could be a fire department that makes that decision. And that's a discussion, right? So you need to make sure that they understand the pieces, but an important part of this process is. Third party, peer reviews. Because if you sit from, if you look at it from a perspective of a department of building or the fire department, they don't necessarily have in-house expertise to deal with all the complexities that could be and to a building, they are infinite, right? No one department, no one person has the answers, right? So at the same time, they need to be able to make decisions that are safe. And there is definitely a healthy level of skepticism that should be there regarding the design team where, okay. You are the design team, but is there any pressure on you to do something that has an economic value, but maybe compromise the safety? That is the job of the department is building to be looking at those questions. And so I think in places like this, bringing. Third party experts from outside who have no interest in a project per se. So they're not swayed by, let's say commercial interests, but they have that expertise could really help the process. That's how seismic performance-based design has been done in the U S and I'm sure in there stuff that world for many years, and it's a process that's that allows people to come to a safe solution that. It's

wojciech_wegrzynski-2021-9-14__20-4-19:

Yeah, I think having discussions is probably the best way. I'm just, I'm really terrified with some of these discussions where, economic benefit or short-term benefit is. That's the objective of some stakeholders to kill the objectives of the other ones. And this is when it usually goes and goes horrible.

Ali Ashrafi:

Just let me hide at something here. In that process, I'm describing the perspective from an authority that has to approve. They always have that concern. And again, you have to have that concern from that perspective. If you come to us as engineers, for example, that's our given the task of life safety, essentially. I see us as in the same function as a doctor has. So your job is to do something that is safe. Are there doctors out there that might make decisions that are not right and influenced by financial interest? Yes, there are. But that would be also a betrayal of their,

wojciech_wegrzynski-2021-9-14__20-4-19:

Yeah.

Ali Ashrafi:

know, there is enough of what they're doing, right? Engineers, good engineers would never compromise safety because of, because of something else. Our job is to do a design that's reasonably. And safe, right? So you don't want to waste resources where it doesn't provide, additional benefits, but providing that baseline level of safety is an absolutely a part of the job and for an engineer to not do that around an architect or a safety official, not that it would never happen, but it's something that's obviously against ethics and laws and all that.

wojciech_wegrzynski-2021-9-14__20-4-19:

Yeah. Okay. Let's move away from objectives for w for a while. In one

Wojciech Wegrzynski:

of your talks you have

wojciech_wegrzynski-2021-9-14__20-4-19:

mentioned something that

Wojciech Wegrzynski:

took my interests.

wojciech_wegrzynski-2021-9-14__20-4-19:

And it may be the reason why I am talking about firefighter safety with the structural fire engineer. And, this was the concept of how the decisions shape the firefighting context, like design decisions, because, The way, how we build the buildings will determine the way, how the fire can be fought in there. You mentioned the word battleground, building is the battleground for the fire. Either fire emerges in it and if everything plays right, the battleground is in favor of the firefighters and can help them. If we take some decisions, we can make the battleground tougher for the firefighters and, the

Wojciech Wegrzynski:

environment is pacing at an

wojciech_wegrzynski-2021-9-14__20-4-19:

insane speed with new technologies, new challenges that were not there 30 years ago. For start of this part of the interview, from your perspective, what are the key aspects in which the design truly does influence the firefighting context? In what way? Us designing the building? outcome in terms of how the fire can be fought into the building.

Ali Ashrafi:

There are a few factors and some of this I've hit on before, but starting from maybe level of importance, I would say a building stability because that's the context, right? And that's something where it's not just about building stability, but knowledge of building stability. So let's say if you have a building and maybe the building ends up standing for the duration, but if you don't know that, and that question, mark is there, you have to make other decisions, right? Because again, these are questions of life safety. Quantified knowledge of building stability is certainly one of those things. There are rules of thumb for firefighters for that. But if you look at these more complex buildings, a lot of those rules of thumb might not be really applicable. So being able to know, okay, if I go into this building and for this type of fire The building will stand or if that's not the case, I'll have 60 minutes. I have 30 minutes. I have 90 minutes, but based on an analysis, I think that would be.

wojciech_wegrzynski-2021-9-14__20-4-19:

And going into the building

Wojciech Wegrzynski:

stability a little deeper. It's

wojciech_wegrzynski-2021-9-14__20-4-19:

also not how long the building will stand, but how much a warning time it will give to the firefighters before it collapses. So, this advanced, uh, it was also something from your talks today that really resonated with me that we just. Just need the 90 minutes of stability because there is no timer. The firefighter doesn't know if it's 89th minute or something. It's also in the matter that the failure is not like immediate, it's a progressive collapse. For example, that gives a warning that people can exit.

Ali Ashrafi:

Correct. So that's one context building stability related to that, which we talked about is evacuate. You need to be able to get people out of the building safely. And if there's a question there, then the firefighters will put their lives at risk to do whatever they can. They're right. And right here, again, there's interplay between how these designs are, what you have regarding how quick it is to evacuate people or how long it takes, can have an impact on building stability and vice versa. So those are two overarching

wojciech_wegrzynski-2021-9-14__20-4-19:

So from a designer perspective, you mean the stability in terms of how the structure is designed, was the load bearing capacity. What are the paths to spread the loads and stuff like that was the structural protection of the critical elements from the fire and from the egress is how we shape the pathways or how

Ali Ashrafi:

all of that. So let's say for the evacuation. Okay. Even explicitly analyzing that. So if you look at a lot of, what we do in the building, really the goal of the code, the first goal of the code is to get people from the immediate area next to the fire, to some area that's somewhat protected by barriers or roles. That's something that happens in seconds and in. When you get there, whether or now the bill people can actually get out of the building or not is not an explicit part of the code. You don't actually analyze that. But we could. Right. And it could be really relevant even within a floor. The provision, the provisions of the code are still prescriptive. So the code tells you have these many path to your egress so have I say to two independent means, then they might have to be separated, but by this much, but you don't actually analyze, what's going to happen in a real fire. And from analysis, we know that you might have code compliant buildings. And at the same time, if there's a fire, just because of the unique design of the. Not everyone might get out to safety. So the problem is these Arctic and not explicit goals of the design. They're implicit. We do things to minimize the risks, but we don't explicitly designed for them. So that's evacuation and building safety, but then you look at the other pieces. Certainly the nature and spread off the fire has an impact, right? And that's, again, something that is impacted by how we design the building in terms of the materials that we use, the layout of the building, an open building versus a compartmentalized building. And I'm not saying you have to do one versus the other. It's just the design decisions have an impact.

wojciech_wegrzynski-2021-9-14__20-4-19:

You need to know what will happen in the building in terms of the course of the fire. And I don't know if it's a thing but in Europe we will. We are also, for all open plan compartments, we're using this

Wojciech Wegrzynski:

traveling fire methodology to determine

wojciech_wegrzynski-2021-9-14__20-4-19:

plenty of possible scenarios in a building to see how they will affect the structure of the building. And it's something we start to truly consider. And it was also a big,

Wojciech Wegrzynski:

not travelling fires

wojciech_wegrzynski-2021-9-14__20-4-19:

because that's new, but this compartment fire behavior was also a significant part of Eurocodes. And it was one of the big, funding

Wojciech Wegrzynski:

things in the Eurocodes. There is

wojciech_wegrzynski-2021-9-14__20-4-19:

the

Wojciech Wegrzynski:

standard fires, curves but there

wojciech_wegrzynski-2021-9-14__20-4-19:

are localized fires that you can calculate with it. And you take this compartment, fire dynamics into equation, and as an

Wojciech Wegrzynski:

engineer, you truly craft that if you like

wojciech_wegrzynski-2021-9-14__20-4-19:

it or not, but shaping your building, you're shaping the possible fire outcomes. So, okay. The third thing is the nature and spell of fire?

Wojciech Wegrzynski:

Is there a fourth thing?

Ali Ashrafi:

Sure. I can add, there are a few more things that are really

wojciech_wegrzynski-2021-9-14__20-4-19:

let's go. Yeah.

Ali Ashrafi:

I think another factor is really how common or how familiar a fire is. So if you think about that, when you have put yourself in the shoe of a firefighter and you have to make decisions, these decisions are guided by your training or by your past experience. And those are heavily guided by the more frequent fires that we see. But if you come to it, how many really large, uncontrolled or hard to control fires in these larger complex buildings in your lifetime. And how many of them do you see to be able to generalize from them? Luckily, not a lot. And that goes back to, we're doing a great job in terms of doing other things with, with fire safety measures, with sprinklers and so on to really mitigate the risk. But it also means that when you have a fire that looks different. You have less things to go by. And so that's where doing some of this analysis, doing some of this thinking ahead of time, and then seeing how that should impact operations and training of firefighters is really important. I think that's one area where we could basically cover that gap, which is a good gap that we don't see a lot of these large uncontrollable. But use what we know and model these things and play out different scenarios. And it's not something that just engineers do. It should be where there, and the firefighters are there and we're working together to see this tactic versus a different tactic. What would be the impact on firefighting? So I think that's another, that's another factor there. And if I want to just add one more thing, I think it's the infrastructure of the building and how that allows for firefighting. And again, if you want to break it into components, how long does it take you to get to a place where you can effectively fight a fire? So for a lot of these buildings, you have to walk up the stairs. And so if you put the, put yourself in there in a firefighter shoe, you get to the building, you have very heavy equipment. Most elevators are shut down. Sometimes there's one that you could use. That's actually part of the discussion, having elevators that you could use to get to the place faster, but. By enlarge large, you're walking up the stairs and as you're walking up the stairs, 20, 30, 40 stories, you also have people coming down the stairs because they need to get out. It might take you 30, 40 minutes to get to the place where you can start fighting the fire. That fire looks very different from something that you could have gotten to, after five minutes. So that's important. And then when you get there, all the water that you get is what you get from your standard. And that's, again, that's not explicit to design for that scenario, so it could be right. So if the design is, for example, something that allows you to have enough water where you can fight a fire, that's involving the entire floor, that's better than having a small amount of fire or if you have a building right, again, you're confident that the building is going to stand. And you can assign more people to fighting the fire, as opposed to evacuating the building. And so maybe you can even start going to floors adjacent and focus on controlling the spread of the fire, and you let this for burn and to the extent that you can make a dent into it and you do, but you don't put yourself out in as much. These are things that's really shaped firefighting in a deep way.

wojciech_wegrzynski-2021-9-14__20-4-19:

Yeah, if you don't design them, they're not going to be used. That's the bottom. So the five things you've mentioned, structural stability, egress and rescue the nature of the fire, spread, closing the knowledge gap between the designer and the firefighters and the final one was the firefighting infrastructure. So these five things are how the designers would shape the firefighting context. And I think it's really powerful because there's a lot of. In fact in that list that we truly do. It's our choices it's, and, it should be choice, not just, the default volume that's been placed in a place without giving, a good thought, a standpipe in a small building, of completely different relevance than a standpipe in a skyscraper where there is literally the single only way to give water. Okay. One more thing that I have noted for this is how the battle ground has changed. I have the feeling that, the design is not evolving as quickly as the problems are, , that the codes are very. At least in

Wojciech Wegrzynski:

Europe, in NFPA it's a little

wojciech_wegrzynski-2021-9-14__20-4-19:

bit different. And if you get 2000 people to vote on that change, yet, it gets implemented very quickly I've been there. I've seen that I was highly impressed by the process, but, in general, the codes are very slow in adapting. And if you'd take a look at the buildings today and 10 years ago, it's a completely different. It's different materials. It's different, building envelope, the facades have changed so much and, uh, different ape or tightness, for example, that's already something that completely changes the battleground that the whole fire environment in your building. And for me, the most interesting. Is that buildings are small power plants today. It's not that you just have a few cables to distribute the energy among the building. Now you want to generate the energy on your whole facade, and hopefully even store it in the building in some power bank to sell it at the bigger price when it's needed. And these are recent objectives five years ago, I would not think about this. And today I have to consider it in a way in my design. Obviously we are talking here about very specific buildings in some of your talks, you'd called them the high impact buildings, the ones that are like, it's not the buildings that you should go with prescriptive codes for, because it's this type of a building that really needs to be engineered. But the battle ground is changing and it's changing so quickly is how do feel about it? Is there a way we can cope with that? How we put the firefighter resiliency in this ever-changing landscape?

Ali Ashrafi:

Um, a great question. I think the answer is performance space design, right? Your design has to be relevant to your building. You have to look at the consequences that are applicable to your building. And what is the behavior that's acceptable from the building in its context, in the place and in the city that it is and what that design looks like should be different than. Building to building because each of these buildings is a custom design. When you look at these larger complex buildings, none of them is like the other one. They have similarities, but there are enough differences where for everything else in the design, if you don't take one design and apply it to the other one, we analyze that for fire. It should be the same, but it does need, a more consciousness or. The fact that, okay, you do have these risks that are ever changing. And that performance-based design is something that does allow you to, get to design that safer and better. And then for everyone who's involved to have that conversation, I think there's that presumption of fire safety I think. Fire resistance terminology, you get two hours or three hours of fire resistance. People look at that and generally think, okay, that means three hours of standing in a fire. Whereas a, maybe that's actually not okay for a building. Maybe that shouldn't be acceptable, even if it's three hours, but B that's that presumption is backed by fact, it depends on scenarios in most cases. And I do want to highlight this. In most cases, the prescriptive design does get your building that is safe. And you don't have these frequent massive collapses of buildings and fire. The codes are doing something really well, but we need to be conscious that. Living in ever more complex buildings and ever more complex environments and with a risk that is changing. And so if we want to have resilience and if you want to avoid these low likelihood rare, but high impact scenarios, really the key answer is, to go and explicitly designed for safety, which is performance based design.

Wojciech Wegrzynski:

you know, one of the interviews with, with Benjamin Ralph i've, actually praised that codes are good. And for a second, I thought this is the end of my career as an engineer after 11 years. Of doing performance based engineer I've praised codes for being great. It was in the context of rapid, iterations of building design in which the full PBD it's just impossible to apply.

wojciech_wegrzynski-2021-9-14__20-4-19:

When you want to have a hundred iterations of a building you need some other ways to manage that. But, I agree that a smart performance-based engineering. Just give a ring to the name, performance-based engineering, your engineering performance. That's the base of your engineering. You need to know what performance to expect, and once you. You can do that. I truly think this is of immense value. I also wanted to ask you about this, issues with fire testing that we're testing materials, not systems and so on. I think we're a little running out of time. And I have one question that I want you to answer because you're the only person I know that can answer that. In your bio I've read, you've dealt a lot with earthquake engineering, wind engineering, , From a perspective of like earthquake engineer. Do you see a thing that exists in earthquake engineering that we do not see in fire engineering or some like strict difference that maybe could be applied to fire engineering? I've never talked to an earthquake engineer. We

Wojciech Wegrzynski:

don't have earthquakes in Poland.

wojciech_wegrzynski-2021-9-14__20-4-19:

So maybe in other parts of the world is a bigger field in here. It's just, the damage done by the mines in Silesia region of Poland. But, it's really interesting because you're dealing with also with high impact accidents that destroy buildings , and structural resiliency's important in this case. And I know that the firefighters who attend these events, they also care about structural stability of the buildings post earthquake. One of my colleagues in the office is. An active firefighter and he's a member of earthquake rescue a team of Poland. So when there's a huge earthquake in somewhere in the world, they will just fly to there and they have rescue dogs. And he told me a lot of things about structural stability and how this is the most important thing they assess when entering the area. So as

Wojciech Wegrzynski:

earthquake engineer

wojciech_wegrzynski-2021-9-14__20-4-19:

or structural engineer that covers this seismic activities. You look at the fire engineering and what do you see?

Ali Ashrafi:

I think the way we deal with earthquakes is actually a model for how we should be dealing with fire. So if you look at the context of seismic design a we've been running numbers, we've been doing actual engineering with real numbers

wojciech_wegrzynski-2021-9-14__20-4-19:

Okay, real numbers. I'm going to write that down.

Ali Ashrafi:

That's just not done as part of the code process for buildings and fire. So just doing no real engineering, there is step one. and then when you look at that process, we ha we've had simpler approaches. And then as we've gone through, improvements in our understanding of building behaviors and also for computation on pick capabilities. We've been doing versions of performance-based design. At least I would say from eighties and nineties, and initially it was less formalized. And then over the years we had to have accumulated so much knowledge and expertise where you could really do great a performance based designed for earthquakes and what from that process. And it's really key as performance-based is on, is basically a rational design. You do things that help improve safety. But because of that, it's also an optimum design. It also means you don't do things that are just a cost and do not provide safety. And so you could say I have the same batch of money. I'm going to use it in a more efficient way and get a safer building. Or if you have a same level of safety as your goal, you can get that. Get there with. Money because you're doing a more optimal design. And so I've done performance space, design design in earthquakes, and you go through the process and you can design the building. That's more resilient. And cheaper at the same time. And when you see that, why not do that? It's the same process that you see in fire. We've done studies actually ASC and Charles Pankow foundation. let us study that we were part of along with a few other engineering firms, a few people from academia, really collaborative work, and we looked at four different buildings and what performance-based design would look for them versus prescriptive design. And in all four cases, I would say there, there are running themes. One of them was performance-based design is not scary. It doesn't put an impossible burden on the design in software design. You also saw safety gaps in the prescriptive design, but in most cases, when you look at the performance design, yes. More resilient and cheaper at the same time. And so that's something to really kind of keep in mind. And then I would say that one more way where seismic design should really be a mother for us is even 10, 15 years ago. When you looked at a performance based design, we did. performance-based designed for very select number of. Most buildings were still prescriptive. We did real engineering, but it was not the same level of sophistication. Nowadays, when you go to a high seismic area and you look at any major building performance-based design has become the norm. So for fire, I'm hoping from going from a prescriptive designed to looking at the important buildings, high consequence buildings with real engineering and during the performance space design. And I think that's something that's really good benefits. What we do.

wojciech_wegrzynski-2021-9-14__20-4-19:

That's perfect. It's so in line with the previous interviews, you have not heard, it seems that, the smart minds in the fire science think alike, and I really enjoy

Wojciech Wegrzynski:

that. Okay, Ali thank

wojciech_wegrzynski-2021-9-14__20-4-19:

you so much for your time. It was a huge pleasure to discuss structural fire resiliency with you It's going to be an important topic for people to just to reach the knowledge. You've mentioned no closing the knowledge gap and reaching the firefighters is important. And it's something I'm thinking out of this interview. So, thank you so much for being here for spending your time with me. And, maybe you have some resources you want people to redirect to, I'm going to redirect them to that great webinar you gave on

Wojciech Wegrzynski:

the structural fire resiliency. But,

wojciech_wegrzynski-2021-9-14__20-4-19:

if there's something else you can let.

Ali Ashrafi:

Sure. I will certainly send you a few links where a lot of people are working on different aspects of this. And so there are resources out there. It's not like we want to start from zero. I also want to thank you, not just for having me here, but I think what you're doing here in having conversations with people who are touching fire safety from different aspects and perspective is really important because this is a problem that has many aspects and the solutions should be talking to each other, and you're really helping doing that. So thank you. So.

wojciech_wegrzynski-2021-9-14__20-4-19:

Thank you. Thank you for the kind words and yeah, let's make the world a little bit safer together.

Wojciech Wegrzynski:

Thank you, Ali. See you around,

Ali Ashrafi:

Thank you.

Wojciech Wegrzynski:

And that's it. I hope you enjoyed this. Talk with Ali about how buildings can be resilient for fighting. And support firefighting. For me to some very interesting discussion with many good points on how can we improve design taking into account the factors that influenced the firefighting actions starting with. Our decisions shaped the battle ground through the role of structural soundness of the building and the structural stability of it and how that influences the firefighters actions and the ability to rescue people the building and finishing with how performance-based engineering is the root for all the good solutions that Ali mentioned. As I understand for Ali, the fire performance-based engineering is the engineering itself and the way how we can design not only safer buildings, but also cost optimized buildings. That's a really profound thought and they also have. In my own career. It's very rare that we would improve safety systems in the building, putting in an additional cost on the building. We usually on our way to that better solutions found ways to make the building cheaper or the solutions cheaper. So it was always a win-win solution for the safety and for the investor. And I'm really happy that he so explicitly put that on the plate. Performance-based engineering. This not only allow you to make the building safer, but only gives this economical incentive to pursue this goal. And. Having my experience, 11 years in building designs in solving practical issues with buildings. I know that sometimes without economical incentive, there's very little you can do so. Thanks Ali. That's a really great fault for all of us. And. Yeah, I hope this can be placed into the practice. And this can be used, as I've mentioned in the intro, Allie has given a lot of practical recommendations that fulfill the prophecies, or they have faults that Brian Meacham has left in the episode 20. So. If you haven't heard episode 20, that's the moment you switch into that and listen to Brian Meacham because these two episodes accompany each other so well. And yeah, I really hope this starts a discussion into how can we build the fire safe world a little better and a little more optimized. And a little more reasonable way, without spending excessive amount of resources on solutions that don't provide anything and truly focusing on objectives that we would all consider us the safety objectives. Thank you so much for listening. As usual please share this episode or this podcast with a friend with a colleague. And, I would love to reach as many people as possible with the messages we have in here. If you think it was valuable for you to spend an hour listening to this episode or the podcast and, it may be also worth for your colleague. Please share the knowledge about the existence of this show. And if you're thriving for more fire science, knowledge and entertainment, please join me next Wednesday. And yeah, there will be another great episode waiting for you there. So yeah. See you next Wednesday. Thanks for being here. Thanks for all of your support cheers.