087 - Structural FSE inspired by earthquake engineering with Negar Elhami Khorasani

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<v Wojciech Węgrzyński>Hello everybody welcome to the Fire Science Show.

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<v Wojciech Węgrzyński>In the fire science and engineering community is not that we always have to come up with solutions from scratch.

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<v Wojciech Węgrzyński>It's always great idea to inspire by success of other groups of engineers.

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<v Wojciech Węgrzyński>Because they may have solved some of the things we are desperately looking for.

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<v Wojciech Węgrzyński>And one of such an inspiration comes from earthquake engineering, community or civil engineering related to earthquakes.

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<v Wojciech Węgrzyński>Who are using performance base engineering and in fact, probabilistic performance based engineering, a lot in their practice.

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<v Wojciech Węgrzyński>And that inspired some fire engineers to try.

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<v Wojciech Węgrzyński>And use that approach for fire safety.

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<v Wojciech Węgrzyński>And as you may guess, that's exactly the subject of today's episode.

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<v Wojciech Węgrzyński>I have invited Dr.

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<v Wojciech Węgrzyński>Negar Elhami Khorasani University of Buffalo to talk about the use of probabilistic approaches in structural fire engineering.

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<v Wojciech Węgrzyński>I know structural fire engineering is already advanced thing on its own.

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<v Wojciech Węgrzyński>And here we are going one step above in the complexity, but trust me, it's worth it.

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<v Wojciech Węgrzyński>You will learn a lot of interesting stuff related to building performance in fire, which in essence is some sort of.

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<v Wojciech Węgrzyński>Distribution of possible scenarios and damage and failure rates.

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<v Wojciech Węgrzyński>It's very natural to position that as a, as a probabilistic problem.

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<v Wojciech Węgrzyński>And that's what we're going to talk today.

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<v Wojciech Węgrzyński>We're not going to talk about probabilities.

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<v Wojciech Węgrzyński>We are going to discuss a framework.

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<v Wojciech Węgrzyński>A really useful tool that can be directly applied to engineering.

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<v Wojciech Węgrzyński>So even if you're not very interested in instructional fire engineering, I hope that this topic will be interesting to you because this framework can be adapted for any other body of.

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<v Wojciech Węgrzyński>Fire safety engineering, I guess now, before I let you into the podcast episode,  I have to share some stuff about the podcast.

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<v Wojciech Węgrzyński>I have to look into statistics.

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<v Wojciech Węgrzyński>The January is ending and I am absolutely astonished with the.

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<v Wojciech Węgrzyński>Growth of the show who there has been over 5,000 listens to the podcast in January.

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<v Wojciech Węgrzyński>That's the best month ever by far in the show.

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<v Wojciech Węgrzyński>And it makes me very, very happy that the podcast is reaching.

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<v Wojciech Węgrzyński>So many engineers.

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<v Wojciech Węgrzyński>I also see a lot of traffic on older episodes.

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<v Wojciech Węgrzyński>That means a lot of people are listening through the whole of the show, which also is a good indication that.

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<v Wojciech Węgrzyński>You like it.

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<v Wojciech Węgrzyński>And, uh, I see a lot of new people in the podcast.

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<v Wojciech Węgrzyński>Uh, And that that makes me truly, truly happy.

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<v Wojciech Węgrzyński>So I have not had the chance to, to welcome all of you new listeners to the Fire Science show.

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<v Wojciech Węgrzyński>So please feel welcomed to this family.

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<v Wojciech Węgrzyński>I hope the podcast is useful to you.

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<v Wojciech Węgrzyński>I hope you find a lots of great resources in a year.

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<v Wojciech Węgrzyński>I tried to be very responsive to those.

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<v Wojciech Węgrzyński>And I really try to incorporate what I learned from you.

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<v Wojciech Węgrzyński>So if you're a new here if you're old commer I hope the podcast is meeting your expectations and you enjoy it a lot now in off of my rambling, because there's a great episode.

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<v Wojciech Węgrzyński>Off today.

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<v Wojciech Węgrzyński>Well, that's been the intro and jump into it as always, I would like to express my gratitude to the, OFR Consultants who are a sponsor and the partner of this podcast.

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<v Wojciech Węgrzyński>OFR Consultants are a multi award-winning independent consultancy dedicated to addressing fire safety challenges.

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<v Wojciech Węgrzyński>OFR is the UKs leading fire risk consultancy is globally established team has developed a reputation for preeminent fire engineering expertise.

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<v Wojciech Węgrzyński>With colleagues working across the world to help protect people, property and planets in the UK.

00:04:04.693 --> 00:04:08.203
<v Wojciech Węgrzyński>That includes the redevelopment of the print with building in Canada water.

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<v Wojciech Węgrzyński>One of the tallest residential buildings in Birmingham, as well as historic structures.

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<v Wojciech Węgrzyński>Like the National Gallery National History Museum and the National Portrait Gallery in London.

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<v Wojciech Węgrzyński>Internationally.

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<v Wojciech Węgrzyński>It's word ranges from Antarctic data.

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<v Wojciech Węgrzyński>Comma desert in Chile.

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<v Wojciech Węgrzyński>And the number of projects across Africa In 20, 23, OFR will grow its team, And it's keen to hear from industry professionals who want to collaborate on fire safety futures this year.

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<v Wojciech Węgrzyński>Getting touch@oilforconsultants.com.

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<v Wojciech Węgrzyński>And now back to your episode on probabilistic, structural fire engineering.

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<v Wojciech Węgrzyński>Hello everybody.

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<v Wojciech Węgrzyński>Welcome to Fire Science Show.

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<v Wojciech Węgrzyński>Today I'm here with Dr Negar Elhami-Khorasni from University of Buffalo.

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<v Wojciech Węgrzyński>Hello Nagar.

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<v Negar Elhami Khorasani>Hi Wojciech,.

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<v Negar Elhami Khorasani>Thank you so much for having me.

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<v Negar Elhami Khorasani>Uh, it's a pleasure for me to, participate in this fire science show.

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<v Wojciech Węgrzyński>that's so Uh, very happy to meet you to do this interview.

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<v Wojciech Węgrzyński>the topic I've proposed for the today's talk is on, probabilistic structural fire engineering, which I guess is, uh, step up from just structural fire engineering, I guess is, is gonna be, Interesting.

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<v Wojciech Węgrzyński>I've had an episode with Thomas structural fire engineering on the podcast, but maybe we could give a short introduction to anyone who missed that one to, uh, what a structural fire engineering, uh, is and how it differentiates from, this typical code-based, fire engineering we used to.

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<v Wojciech Węgrzyński>So, so let's start with structural fire engineering, and then we're gonna up the game to the probabilistic one.

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<v Negar Elhami Khorasani>Sure, definitely.

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<v Negar Elhami Khorasani>I listened to your podcast with, Thomas, uh, great, uh, friend and colleague, and I w wouldn't be able to beat him on that definition, but I'll try.

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<v Negar Elhami Khorasani>So, to put on perspective for, For your audience.

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<v Negar Elhami Khorasani>Uh, the prescriptive approach, we all know it's basically you follow the code, uh, or the rules and it's presumed that it provides acceptable performance.

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<v Negar Elhami Khorasani>Uh, but we don't actually check what performance we're gonna get at overall the structural system, whereas with, Structural Fire Engineering, or I'm gonna link it to performance based design is basically a procedure that, it enables the design of the structure, whether it's a building, whether it's a tunnel, whether it's a bridge, that you look at the performance of the structure and you make sure to get this predefined or desirable performance, whatever that is, that's set acceptable for project.

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<v Wojciech Węgrzyński>Yeah, and I, I know in the US, a lot of people are doing a lot of effort to make performance based, uh, structural fire engineering, um, a thing in, in the design.

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<v Wojciech Węgrzyński>So, so maybe let's, let's take it, uh, A little step further.

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<v Wojciech Węgrzyński>What, what, what does it enable?

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<v Wojciech Węgrzyński>Like what's, what's the benefit of, of me if I'm a, I'm a billion dollar investor in my building and I want, I would like to go that path.

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<v Wojciech Węgrzyński>How, how would you sell it to me?

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<v Wojciech Węgrzyński>Is it even

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<v Negar Elhami Khorasani>Right, right.

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<v Negar Elhami Khorasani>as part of, again, the academia, when we talk about it, we definitely focus a lot on the safety side.

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<v Negar Elhami Khorasani>And we say, okay, with, um, advances in new materials, in new, different techniques and structural systems, it's definitely.

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<v Negar Elhami Khorasani>Safer if you design using structural fire engineering so that you know, uh, how the structure would perform.

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<v Negar Elhami Khorasani>Uh, once we start talking with the industry.

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<v Negar Elhami Khorasani>However, we definitely also bring in the aspect of economy and how it makes sense for the industry to, invest, uh, in the approach because they could, uh, save money.

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<v Negar Elhami Khorasani>One of the examples that.

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<v Negar Elhami Khorasani>Demonstrated, not necessarily in terms of, we haven't, quantified the cost yet, but in terms of, uh, quantity of material, for example, it's this composite floor system that, even with, one of your, uh, podcasts on BRE and CARDINGTON test and the work that they've done, here in the US V also adopted that.

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<v Negar Elhami Khorasani>Sort of knowledge to the US system and said, said, okay, let's say you've got composite floor system.

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<v Negar Elhami Khorasani>You've got this beam steel beams and steel girders, and then concrete slab on top.

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<v Negar Elhami Khorasani>If you remove the insulation on, uh, the beams, interior beams, you do not necessarily, have issues with.

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<v Negar Elhami Khorasani>the fire safety side.

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<v Negar Elhami Khorasani>And then if you have a multi-story structure, then imagine how much installation you're saving.

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<v Negar Elhami Khorasani>Not just in terms of material, but also the labor cost of applying that, um, installation.

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<v Negar Elhami Khorasani>So these are some of the cases that we actually, through this.

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<v Negar Elhami Khorasani>Um, there was a project, in the US again, foreign industry, uh, companies got involved and one of the primary.

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<v Negar Elhami Khorasani>systems that they looked at was this type of system and then they applied structural fire engineering compared it with prescriptive approach and showed that okay, they're actually buildings.

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<v Negar Elhami Khorasani>Fulfill the requirement even if the installation was not applied everywhere.

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<v Negar Elhami Khorasani>So it, that's the economy side of things.

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<v Negar Elhami Khorasani>but uh, we also have challenges in the US , so it's not just all good stories.

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<v Negar Elhami Khorasani>Uh, we, in the US we are, um, pushing towards structural fire engineering at this stage.

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<v Negar Elhami Khorasani>Uh, it is officially in the code.

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<v Negar Elhami Khorasani>Uh, we have this A S C E seven.

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<v Negar Elhami Khorasani>it describes all the loads.

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<v Negar Elhami Khorasani>Uh, so in the appendix, this performance based design for fire.

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<v Negar Elhami Khorasani>So, but now it means that it's official and, industry can use it.

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<v Negar Elhami Khorasani>however, uh, what we are trying to do as part of the community here in the US is to, spread the knowledge.

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<v Negar Elhami Khorasani>and train a workforce because until we have enough people who are comfortable using structural fire engineering, it probably won't, um, get used too much.

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<v Negar Elhami Khorasani>So that's another, aspect that we are trying to contribute to, to make sure that this concept gets established in the.

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<v Wojciech Węgrzyński>I wonder within the current paradigm of, fire testing of, structural performance of the building being the defined, uh, in terms of, you know, classes, ratings as it is now Given the pace of, of the development of new technologies, new solutions, new materials.

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<v Wojciech Węgrzyński>at some, at some point, it must a factor that either slows down or a factor in which, uh, risky solutions get passed through because someone gamed the index and, and they found a way I, I guess, , if you look at it from this point of view, I, I guess fire engineering is inevitable.

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<v Wojciech Węgrzyński>I wonder how long the paradigm can sustain.

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<v Wojciech Węgrzyński>What, what's your thoughts on this  challenge?

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<v Wojciech Węgrzyński>Challenging,

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<v Negar Elhami Khorasani>there there are two two potential outcomes here.

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<v Negar Elhami Khorasani>One is that, We manage to push this forward quick enough that, uh, it gets, used and, people keep up with it.

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<v Negar Elhami Khorasani>the other way, which is not perhaps, a positive outcome is, when maybe we get structures that are, we don't know exactly how they perform and then something goes wrong, and then there will be the.

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<v Negar Elhami Khorasani>societal impact and people will not be happy, right?

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<v Negar Elhami Khorasani>As, as soon as, you know, something finds its way in the news and then, everybody would know about it.

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<v Negar Elhami Khorasani>That okay, there was a mistake or there was a lack of knowledge.

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<v Negar Elhami Khorasani>it's definitely not something we want to happen, but often when something like.

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<v Negar Elhami Khorasani>again occurs then, the, the Ians and industry and everybody tries to move quickly and find the solution and say, okay, now sorry, we should have done this.

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<v Negar Elhami Khorasani>Okay, maybe now it's time to adopt structural fire engineering.

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<v Negar Elhami Khorasani>So, uh, hopefully we end up with Path one, where, we realize how important it is, as a community and.

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<v Negar Elhami Khorasani>try to again, develop the competency to use it, uh, across, nation The, One, um, challenge we are facing here in the US is that, um, so a lot of people realize that how important it is.

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<v Negar Elhami Khorasani>And, when I talk about structural foreign engineering, it's not about, okay, every single building needs to be designed using structural farming.

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<v Negar Elhami Khorasani>It's just not.

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<v Negar Elhami Khorasani>May be worth it if you have a two, three story structure.

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<v Negar Elhami Khorasani>If it's a regular structure, that's not the argument we are trying to make here.

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<v Negar Elhami Khorasani>That okay, you, you have to apply for it and prescriptive design is gone.

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<v Negar Elhami Khorasani>No, no, no, no, no.

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<v Negar Elhami Khorasani>That's not the idea.

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<v Negar Elhami Khorasani>It's about all these special cases or cases that it's, the prescriptive approach will not provide a, perhaps a safe design.

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<v Negar Elhami Khorasani>then may maybe people start listening.

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<v Wojciech Węgrzyński>Yeah.

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<v Wojciech Węgrzyński>But, but with the variety of materials, the variety of solutions, the, uh, creativity of architects, uh, and just having, uh, Puzzle as an enabler for creativity.

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<v Wojciech Węgrzyński>You know, because there is a way you can, uh, maybe make a very interesting building, which was prohibited because of the rigid, requirements of the code before.

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<v Wojciech Węgrzyński>Maybe that's something that would push for, for more creativity in this space.

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<v Wojciech Węgrzyński>And the more of this variety comes in, the, the more, the bigger role structural fire engineering.

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<v Wojciech Węgrzyński>uh, that, that's already a big jump from something where you, um, assume the safety or acceptable performance to the point where you measure acceptable performance.

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<v Wojciech Węgrzyński>And now let's make another leap into the probabilistic aspect.

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<v Wojciech Węgrzyński>So wh where does the probabilistic aspect comes from?

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<v Wojciech Węgrzyński>What does it replace in the.

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<v Wojciech Węgrzyński>Paradigm of structural foreign engineering and in, in general may.

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<v Wojciech Węgrzyński>Maybe let's start with how did you start working on this?

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<v Wojciech Węgrzyński>As what, what made you think that this worth spending many years of your career investigating?

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<v Wojciech Węgrzyński>Yeah.

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<v Negar Elhami Khorasani>Sure.

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<v Negar Elhami Khorasani>Uh, it actually for me started, as part of my PhD.

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<v Negar Elhami Khorasani>I started 2010 and a lot of my thinking has been influenced, by the work in earthquake engineering.

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<v Negar Elhami Khorasani>So, well performance based design in earthquake engineering.

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<v Negar Elhami Khorasani>it's mature relatively to, you know, structural fire engineering and, it breaks down the problem.

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<v Negar Elhami Khorasani>Into these four boxes.

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<v Negar Elhami Khorasani>They call it hazard analysis.

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<v Negar Elhami Khorasani>Structural analysis, fragility analysis, which is equivalent to damage, quantification of damage, and then loss analysis.

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<v Negar Elhami Khorasani>So these four boxes, they're linked together.

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<v Negar Elhami Khorasani>So they, you start from hazard, you go to analysis, structural analysis, then fragility, then loss, and uh, each box is a model or set.

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<v Negar Elhami Khorasani>Uh, and these models depend on uncertain inputs.

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<v Negar Elhami Khorasani>They're, they, they're not necessarily deterministic, they can be right.

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<v Negar Elhami Khorasani>But, uh, within the probabilistic approach, each box has its own uncertain inputs and parameters that produces a probabilistic outcome.

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<v Negar Elhami Khorasani>and then the probabilistic outcome of One Box feeds into, uh, the next box, which itself could also have other, specific probabilistic inputs.

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<v Negar Elhami Khorasani>if, if I wanna explain each box within the structural fire engineering, uh, world, the first one I.

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<v Negar Elhami Khorasani>Trivial, it's the hazard box.

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<v Negar Elhami Khorasani>So it's about modeling the fire scenarios and the likelihood of those events.

00:15:06.035 --> 00:15:07.515
<v Negar Elhami Khorasani>So we won't stop us saying that.

00:15:07.515 --> 00:15:07.836
<v Negar Elhami Khorasani>Okay.

00:15:07.885 --> 00:15:11.125
<v Negar Elhami Khorasani>we're gonna have, let's say, a compartment inside a building.

00:15:12.030 --> 00:15:15.850
<v Negar Elhami Khorasani>And it has a one fuel low density.

00:15:15.850 --> 00:15:22.211
<v Negar Elhami Khorasani>It has one ventilation factor, and let's use, you know, parametric model and we get a temperature time care.

00:15:22.211 --> 00:15:23.490
<v Negar Elhami Khorasani>We, it won't stop at that.

00:15:23.852 --> 00:15:26.244
<v Negar Elhami Khorasani>there are inputs to that box.

00:15:26.553 --> 00:15:29.244
<v Negar Elhami Khorasani>I mentioned two of them, ventilation and fuel, low density.

00:15:29.244 --> 00:15:34.760
<v Negar Elhami Khorasani>Now we make them, we assign a, uh, distribution to those.

00:15:35.567 --> 00:15:41.768
<v Negar Elhami Khorasani>and therefore instead of getting one temperature time curve we get a series of temperature, time curves

00:15:42.210 --> 00:15:44.950
<v Wojciech Węgrzyński>So here, In, uh, the previous paradigm?

00:15:44.950 --> 00:15:47.586
<v Wojciech Węgrzyński>Or, or just, just the basic way of thinking.

00:15:47.586 --> 00:15:53.313
<v Wojciech Węgrzyński>You would have a scenario that is described either by the code, which could be like, um, standard fire.

00:15:53.943 --> 00:15:56.943
<v Wojciech Węgrzyński>Curve, which, which also is a, is, is kind of a scenario.

00:15:57.193 --> 00:16:02.884
<v Wojciech Węgrzyński>Or you could use some sort of model, like a zone model or CFD model to come up with your temperature.

00:16:02.884 --> 00:16:08.764
<v Wojciech Węgrzyński>But then again, you are limited here to what you've put into the model, which was most likely a certain.

00:16:09.154 --> 00:16:17.085
<v Wojciech Węgrzyński>Data point, like a fuel load, like you said, a ventilation factor, where in reality it's like, uh, hundreds of outcomes that that can come up.

00:16:17.174 --> 00:16:25.969
<v Wojciech Węgrzyński>So how, how do you define them in this probabilistic framework you provide ranges of, of these values and where do you take these ranges from?

00:16:26.183 --> 00:16:26.854
<v Negar Elhami Khorasani>exactly.

00:16:27.144 --> 00:16:29.399
<v Negar Elhami Khorasani>So, there are a couple of, points here.

00:16:29.399 --> 00:16:31.399
<v Negar Elhami Khorasani>One is, uh, correct.

00:16:31.399 --> 00:16:37.326
<v Negar Elhami Khorasani>First you, As a user of this procedure, you have to decide which model you want to use.

00:16:37.767 --> 00:16:45.580
<v Negar Elhami Khorasani>and as you uh mentioned, it can range from, okay, the, well, I'm gonna set aside the standard fire curve because that's just set.

00:16:45.580 --> 00:16:47.914
<v Negar Elhami Khorasani>But from, let's that's, that's,

00:16:47.914 --> 00:16:49.634
<v Wojciech Węgrzyński>where you should go,.

00:16:49.075 --> 00:16:49.634
<v Wojciech Węgrzyński>Negar Elhami Khorasani: Sorry.

00:16:49.679 --> 00:16:50.240
<v Wojciech Węgrzyński>Right.

00:16:51.210 --> 00:16:59.960
<v Wojciech Węgrzyński>So that aside, we have the perme, maybe temperature time curve all the way to, we could have CFD model, we could have Z Zone models in between.

00:16:59.960 --> 00:17:12.027
<v Wojciech Węgrzyński>So the level of complexity, uh, differs and therefore the l different, each model records different inputs with, let's say, the perme, fire, we list all the inputs.

00:17:12.535 --> 00:17:13.404
<v Wojciech Węgrzyński>We could do.

00:17:13.454 --> 00:17:18.125
<v Wojciech Węgrzyński>So I'm kind of gonna deviate now for each of, uh, these models.

00:17:18.424 --> 00:17:20.404
<v Wojciech Węgrzyński>You can do a sensitivity analysis.

00:17:20.404 --> 00:17:20.964
<v Wojciech Węgrzyński>That's the first.

00:17:21.015 --> 00:17:23.244
<v Wojciech Węgrzyński>So you, you say, okay, these are all my inputs.

00:17:23.244 --> 00:17:27.484
<v Wojciech Węgrzyński>Now I need to, it's not one, one value per input.

00:17:27.484 --> 00:17:29.605
<v Wojciech Węgrzyński>There's a range now for each of them.

00:17:30.265 --> 00:17:31.545
<v Wojciech Węgrzyński>let's say few load.

00:17:32.075 --> 00:17:33.924
<v Wojciech Węgrzyński>that was a study by itself.

00:17:34.005 --> 00:17:38.525
<v Wojciech Węgrzyński>We've spent, um, a year or two just looking at survey.

00:17:39.259 --> 00:17:46.930
<v Wojciech Węgrzyński>Surveys that are out there, fuel load density surveys, and try to quantify the uncertainty in fuel load density.

00:17:46.930 --> 00:17:49.329
<v Wojciech Węgrzyński>And it's not an easy task because it varies.

00:17:49.329 --> 00:17:59.753
<v Wojciech Węgrzyński>It's based on occupancy and, um, it could change based on country even because the type of loads you may have, the type furniture you may have.

00:17:59.753 --> 00:18:02.277
<v Wojciech Węgrzyński>It kind of, it may vary from place to place.

00:18:02.352 --> 00:18:09.882
<v Wojciech Węgrzyński>Even stuff like company culture, like one company would have a clean desk policy and keep everything in, in, in closets.

00:18:09.882 --> 00:18:13.842
<v Wojciech Węgrzyński>Others would like, well, like my, my desk is not very clean

00:18:14.402 --> 00:18:16.152
<v Negar Elhami Khorasani>No, I, we actually encountered that.

00:18:16.152 --> 00:18:16.897
<v Negar Elhami Khorasani>We did office.

00:18:16.919 --> 00:18:19.328
<v Negar Elhami Khorasani>just, uh, parenthesis as part of this discussion.

00:18:19.679 --> 00:18:30.142
<v Negar Elhami Khorasani>um, there was a study, uh, supported by National Fire Protection Association and fba, and um, actually this study was, collaborative, project with Thomas Gnet, professor Gnet.

00:18:30.142 --> 00:18:38.182
<v Negar Elhami Khorasani>And we, wanted to apply a new method to survey, uh, field Density, but I'm gonna jump into the conclusion.

00:18:39.112 --> 00:18:40.551
<v Negar Elhami Khorasani>because that's relevant to this discussion.

00:18:40.721 --> 00:18:58.654
<v Negar Elhami Khorasani>We, uh, surveyed offices at universities because we were just, the point of that project was to develop the meta methodology, not necessarily getting, you know, a few low density and, apparently, uh, admissions, we have a lot of books and papers and exam notes and all of that.

00:18:58.865 --> 00:19:04.575
<v Negar Elhami Khorasani>So the amount of fuel, uh, density that we calculated was much, much higher.

00:19:04.845 --> 00:19:06.775
<v Negar Elhami Khorasani>Than perhaps what's in the code.

00:19:06.775 --> 00:19:11.335
<v Negar Elhami Khorasani>And, uh, what we had expected because a lot of paper and those papers all burn.

00:19:11.944 --> 00:19:18.055
<v Negar Elhami Khorasani>Uh, so it, again, if it was under category of office, but it was just an office inside a university building,

00:19:18.444 --> 00:19:18.934
<v Wojciech Węgrzyński>Okay.

00:19:19.565 --> 00:19:20.414
<v Wojciech Węgrzyński>A different type of

00:19:20.494 --> 00:19:21.775
<v Negar Elhami Khorasani>different type of office.

00:19:21.775 --> 00:19:24.055
<v Negar Elhami Khorasani>So it makes a difference Indeed.

00:19:24.404 --> 00:19:26.954
<v Wojciech Węgrzyński>So, so you have this different inputs.

00:19:26.954 --> 00:19:27.755
<v Wojciech Węgrzyński>Let, let's continue on.

00:19:28.559 --> 00:19:30.670
<v Negar Elhami Khorasani>So you have, um, different inputs.

00:19:30.670 --> 00:19:37.967
<v Negar Elhami Khorasani>So fuel, again, you do surveys, ventilation, you still have to assign a distribution, uh, with ventilation.

00:19:38.047 --> 00:19:39.606
<v Negar Elhami Khorasani>There are different approaches.

00:19:40.392 --> 00:19:42.461
<v Negar Elhami Khorasani>If you really don't know, I'll give an example then.

00:19:42.461 --> 00:19:48.595
<v Negar Elhami Khorasani>If you really don't know and, you could still make engineering judgment in the sense that there's a minimum, there's a maximum, right?

00:19:48.595 --> 00:19:54.234
<v Negar Elhami Khorasani>Because you've got windows, you've got doors, and you can assume that, okay, it will vary within that range.

00:19:54.234 --> 00:19:56.035
<v Negar Elhami Khorasani>It's not gonna be outside of that range.

00:19:56.788 --> 00:19:59.778
<v Negar Elhami Khorasani>So knowing those inputs, you put it into the model.

00:19:59.778 --> 00:20:03.138
<v Negar Elhami Khorasani>There's also, if you wanna make it, you know, really complete.

00:20:03.138 --> 00:20:18.224
<v Negar Elhami Khorasani>There's also the model uncertainty in a sense that, um, if you are working, with a certain zone model or certain C f D, the idealization that goes into the model also makes a difference in terms of the output you're getting.

00:20:18.755 --> 00:20:23.904
<v Negar Elhami Khorasani>So you should be considering some uncertainty on the model side as.

00:20:24.116 --> 00:20:26.549
<v Wojciech Węgrzyński>and, and what's the benefit of going through all this hassle?

00:20:26.549 --> 00:20:28.630
<v Wojciech Węgrzyński>Why not just picking the worst case scenario?

00:20:28.630 --> 00:20:33.950
<v Wojciech Węgrzyński>How does this change your, uh, like what, what's the benefit you get from, from going through this?

00:20:34.474 --> 00:20:45.398
<v Negar Elhami Khorasani>Because at the end of the day, when you go through all the four boxes, you get basically the probability of, uh, having the loss and the distribution of that loss.

00:20:45.848 --> 00:20:50.679
<v Negar Elhami Khorasani>Uh, so rather than getting one value, you're gonna get a distribution and then your performance.

00:20:50.999 --> 00:21:01.791
<v Negar Elhami Khorasani>Objective should technically be defined also, probabilistically in in a sense that, So it's not defined that, okay, for this given worst case scenario, you should have, let's say life safety.

00:21:01.981 --> 00:21:05.991
<v Negar Elhami Khorasani>Life safety is always there, but, um, further performance objectives such as.

00:21:06.902 --> 00:21:08.662
<v Negar Elhami Khorasani>Building should be operational and so on.

00:21:09.071 --> 00:21:16.474
<v Negar Elhami Khorasani>you have it, in a probabilistic way as in, for a hazard with a given, rate of return.

00:21:17.095 --> 00:21:20.875
<v Negar Elhami Khorasani>the expected outcome or loss should be, you know, X.

00:21:21.484 --> 00:21:26.588
<v Negar Elhami Khorasani>So, and you do this because it's just so much uncertainty involve the whole process.

00:21:27.483 --> 00:21:30.554
<v Negar Elhami Khorasani>So that's why you try to, um, actually capture that.

00:21:31.239 --> 00:21:36.659
<v Wojciech Węgrzyński>I also observe that, that we often, when we don't have, very good data, we keep adding.

00:21:37.156 --> 00:21:38.267
<v Wojciech Węgrzyński>Margins of safety.

00:21:39.131 --> 00:21:40.644
<v Wojciech Węgrzyński>They, they multiply by each other.

00:21:40.644 --> 00:21:44.163
<v Wojciech Węgrzyński>You know, if you add in, in, in some steps of your analysis.

00:21:44.163 --> 00:21:48.084
<v Wojciech Węgrzyński>I add, um, a margin of safety to my, uh, Fuel load.

00:21:48.084 --> 00:21:50.203
<v Wojciech Węgrzyński>I add a margin on my evacuation.

00:21:50.203 --> 00:21:52.723
<v Wojciech Węgrzyński>I add a margin, you know, on the structural performance.

00:21:52.943 --> 00:21:54.564
<v Wojciech Węgrzyński>And all of this add together.

00:21:54.564 --> 00:22:00.644
<v Wojciech Węgrzyński>And at the end you don't even know what's the total margin of safety of your building, whi which, which can be actually enormous.

00:22:00.644 --> 00:22:08.027
<v Wojciech Węgrzyński>And when we're talking about, uh, economic gains or, benefit in the end for the client or for for the building is, is by.

00:22:08.400 --> 00:22:13.599
<v Wojciech Węgrzyński>Smart reduction of these safety margins that, could potentially be unnecessary in a way.

00:22:13.599 --> 00:22:20.426
<v Wojciech Węgrzyński>So, so I understand, uh, that, good data is, is, is somehow required to, to, to start forward.

00:22:20.676 --> 00:22:21.666
<v Wojciech Węgrzyński>So you have your.

00:22:22.582 --> 00:22:23.142
<v Wojciech Węgrzyński>Input.

00:22:23.142 --> 00:22:27.061
<v Wojciech Węgrzyński>So you have for, for your hazard analysis, you said there are four boxes.

00:22:27.162 --> 00:22:28.501
<v Wojciech Węgrzyński>I'm gonna reiterate them.

00:22:28.501 --> 00:22:31.838
<v Wojciech Węgrzyński>Hazards, structures, then fragility, which is also damage.

00:22:31.838 --> 00:22:33.118
<v Wojciech Węgrzyński>And then the fourth one, last one.

00:22:33.118 --> 00:22:33.439
<v Wojciech Węgrzyński>Loss.

00:22:33.439 --> 00:22:35.838
<v Wojciech Węgrzyński>The economic loss in that.

00:22:35.838 --> 00:22:39.638
<v Wojciech Węgrzyński>So, uh, moving from just hazards to, to structures.

00:22:39.638 --> 00:22:40.838
<v Wojciech Węgrzyński>What's happening, uh, there.

00:22:41.114 --> 00:22:45.703
<v Negar Elhami Khorasani>so let me just because to connect the four boxes and then I'll go into the second box.

00:22:45.773 --> 00:22:48.784
<v Negar Elhami Khorasani>This is more like a conditional probability type of thing.

00:22:48.784 --> 00:22:50.624
<v Negar Elhami Khorasani>So that's why you kind of break them down.

00:22:50.624 --> 00:22:56.544
<v Negar Elhami Khorasani>So you say, uh, now connecting the first two boxes, you say, well, how is the structure going to performance?

00:22:56.544 --> 00:23:03.144
<v Negar Elhami Khorasani>So what's the probability of having the structure reaching, for example, such and such deflections just making it up given.

00:23:03.828 --> 00:23:04.269
<v Negar Elhami Khorasani>a hazard.

00:23:04.278 --> 00:23:09.909
<v Negar Elhami Khorasani>So now let's say you have thousand different scenarios coming out of the, uh, hazard box.

00:23:10.209 --> 00:23:18.628
<v Negar Elhami Khorasani>But per each scenario, given that scenario, you can start looking at the structural analysis part of it, the the problem.

00:23:19.288 --> 00:23:22.388
<v Negar Elhami Khorasani>And that itself is not going to have one answer per scenario.

00:23:22.388 --> 00:23:24.229
<v Negar Elhami Khorasani>You may have different.

00:23:24.832 --> 00:23:29.471
<v Negar Elhami Khorasani>Given the uncertainties that go into the structural analysis box.

00:23:29.811 --> 00:23:32.951
<v Negar Elhami Khorasani>Now here we are dealing with material properties.

00:23:33.162 --> 00:23:38.751
<v Negar Elhami Khorasani>We are dealing with the applied load on this structure, you know, dead load, live load, and so on.

00:23:39.332 --> 00:23:48.365
<v Negar Elhami Khorasani>And Typically, I'm gonna draw again a parallel line to earthquake engineering or other hazards, the material properties at ambient temperature.

00:23:48.755 --> 00:23:55.634
<v Negar Elhami Khorasani>the uncertainty there compared to the uncertainty in the hazard, which for earthquake engineering is ground motion is much smaller.

00:23:55.805 --> 00:23:58.875
<v Negar Elhami Khorasani>So the uncertainty you get in ground motions much harder.

00:23:58.875 --> 00:23:59.914
<v Negar Elhami Khorasani>So it makes sense.

00:23:59.914 --> 00:24:04.434
<v Negar Elhami Khorasani>If you wanna drop something, you would drop the material property on certainties for fire.

00:24:05.045 --> 00:24:05.835
<v Negar Elhami Khorasani>Um, it's not.

00:24:06.394 --> 00:24:13.261
<v Negar Elhami Khorasani>easy as that because we actually have variation temperature with temperature comes, changing.

00:24:13.592 --> 00:24:23.884
<v Negar Elhami Khorasani>If you have steel yield strength, if you have concrete, you have if privacy, all that, which again, when we collected the data, is a large variability.

00:24:23.884 --> 00:24:28.525
<v Negar Elhami Khorasani>There's a large scatter in the data, so it's hard to drop that.

00:24:28.642 --> 00:24:29.541
<v Negar Elhami Khorasani>Uncertainty.

00:24:29.541 --> 00:24:32.662
<v Negar Elhami Khorasani>Another level of uncertainty going into the structural analysis.

00:24:33.112 --> 00:24:34.602
<v Negar Elhami Khorasani>within, again, fire.

00:24:34.602 --> 00:24:36.442
<v Negar Elhami Khorasani>The first step is always heat transfer.

00:24:36.442 --> 00:24:37.961
<v Negar Elhami Khorasani>Then you do the structural analysis, right?

00:24:38.132 --> 00:24:50.442
<v Negar Elhami Khorasani>So all the properties that go into the heat transfer analysis, such as terminal conductivity of uh, your fire protection, um, and as well as your, again, steel, if you have steel or concrete, they all make a.

00:24:50.993 --> 00:24:57.670
<v Negar Elhami Khorasani>We have done sensitivity analysis and for example, one of the parameters that, came out to make quite a difference.

00:24:57.670 --> 00:25:12.190
<v Negar Elhami Khorasani>So it's hard to make that parameter de deterministic is again, terminal conductivity of the fire protection, which is a variable at least, uh, at this stage is hard to know exactly what it is, which also changes with temperatures.

00:25:12.190 --> 00:25:16.213
<v Negar Elhami Khorasani>So one thing is to get the variable at ambient temperature from, the producer.

00:25:16.703 --> 00:25:18.903
<v Negar Elhami Khorasani>manufacturer of that material.

00:25:18.903 --> 00:25:25.297
<v Negar Elhami Khorasani>Another thing is to actually know the variability with temperature, which there's not much data there.

00:25:25.297 --> 00:25:26.136
<v Negar Elhami Khorasani>That's one thing.

00:25:26.136 --> 00:25:31.910
<v Negar Elhami Khorasani>Another thing is, um, it, it varies from material, but you know, for different materials.

00:25:31.910 --> 00:25:37.349
<v Negar Elhami Khorasani>So, um, something that's hard to drop in this process and make it determin.

00:25:37.534 --> 00:25:39.152
<v Wojciech Węgrzyński>We had similar experiences.

00:25:39.372 --> 00:25:50.944
<v Wojciech Węgrzyński>Our colleagueuh Piotr Turkowski, who was on on the show as well, he produced an internal book of, basic, Properties and there are change in temperatures that, uh, we are secretly using.

00:25:50.944 --> 00:25:53.184
<v Wojciech Węgrzyński>And the same goes with a specific heat.

00:25:53.184 --> 00:25:53.384
<v Wojciech Węgrzyński>Uh,

00:25:53.444 --> 00:25:54.005
<v Negar Elhami Khorasani>Right,

00:25:54.295 --> 00:25:56.664
<v Wojciech Węgrzyński>it's, it's very temperature dependence.

00:25:56.664 --> 00:26:02.144
<v Wojciech Węgrzyński>So there are these funny things you have to start worrying about when you are doing a fire.

00:26:02.315 --> 00:26:08.545
<v Wojciech Węgrzyński>Uh, one, one thing I was wondering, uh, and I've read some of your papers before this interview, you've also done work.

00:26:08.950 --> 00:26:12.394
<v Wojciech Węgrzyński>on, on load modeling and, and, how to define loads.

00:26:12.394 --> 00:26:18.763
<v Wojciech Węgrzyński>And I found that very interesting, that loads are also something that, not, uh, same over many buildings, right?

00:26:18.763 --> 00:26:19.044
<v Wojciech Węgrzyński>And.

00:26:19.153 --> 00:26:20.153
<v Negar Elhami Khorasani>Right, exactly.

00:26:20.173 --> 00:26:25.160
<v Negar Elhami Khorasani>And, uh, actually that paper, we, Ruben, uh, van Coile was, leading that work.

00:26:25.180 --> 00:26:30.356
<v Negar Elhami Khorasani>And the issue we were facing before that paper was that in the literature there were.

00:26:30.902 --> 00:26:33.102
<v Negar Elhami Khorasani>Different models with different assumptions.

00:26:33.721 --> 00:26:40.142
<v Negar Elhami Khorasani>And what happened was that, uh, again, in the literature, you know, we kept either referring to one or the other.

00:26:40.271 --> 00:26:45.285
<v Negar Elhami Khorasani>So, there were a number of papers referring to case a number of papers referring to case B.

00:26:45.295 --> 00:26:48.749
<v Negar Elhami Khorasani>So we, we weren't sure, uh, okay.

00:26:48.749 --> 00:26:51.403
<v Negar Elhami Khorasani>What's the right, probabilistic model we should be using.

00:26:52.334 --> 00:27:07.114
<v Negar Elhami Khorasani>Uh, so we just, went into the background of, those assumptions made, and, Ruben and his student with the larger group, um, Thomas, Danny Hopkin, uh, eventually, arrived at.

00:27:07.778 --> 00:27:14.348
<v Negar Elhami Khorasani>A model that seemed to be most logical, given all the assumptions, again, behind these models.

00:27:14.449 --> 00:27:23.598
<v Negar Elhami Khorasani>And, uh, it does definitely make a difference because I wanna tie it back to one of our more recent studies, so in the US we have prescriptive approach, right?

00:27:23.598 --> 00:27:23.919
<v Negar Elhami Khorasani>And.

00:27:24.489 --> 00:27:36.219
<v Negar Elhami Khorasani>A lot not being applied and we said, okay, let's say you've got a multi-story structure and you have all these columns in across the building, and they're all designed based on a FI rating requirement.

00:27:37.209 --> 00:27:47.038
<v Negar Elhami Khorasani>Now that we have all these models over years, we know developed, let's, quantify probability of reaching a limit state for all those columns across the building.

00:27:47.818 --> 00:28:01.898
<v Negar Elhami Khorasani>And see, we get similar probability because technically if you want to have, what I'm calling it, harmonized safety, you shouldn't have a different, probability of failure on the seventh floor versus the second floor.

00:28:01.898 --> 00:28:02.378
<v Negar Elhami Khorasani>Right.

00:28:02.469 --> 00:28:03.739
<v Negar Elhami Khorasani>It, it's the same building.

00:28:03.753 --> 00:28:06.594
<v Wojciech Węgrzyński>a, or in a, core versus the edge of

00:28:06.644 --> 00:28:07.203
<v Negar Elhami Khorasani>right?

00:28:07.203 --> 00:28:07.723
<v Negar Elhami Khorasani>exactly.

00:28:07.933 --> 00:28:16.156
<v Negar Elhami Khorasani>So we didn't vary much the assumptions on the hazard size because we were saying again, that given, you know, whatever hazard inside a building, what's the probability?

00:28:16.257 --> 00:28:22.130
<v Negar Elhami Khorasani>And, as somewhat expected, the probability of failure actually varies.

00:28:22.557 --> 00:28:27.936
<v Negar Elhami Khorasani>across the building over the um, so two, two things change from, upper floors.

00:28:27.936 --> 00:28:29.136
<v Negar Elhami Khorasani>Let's say two lower floors.

00:28:29.136 --> 00:28:34.096
<v Negar Elhami Khorasani>One is the, uh, section factor or the size of the column because as you go down, gets heavier.

00:28:34.734 --> 00:28:39.240
<v Negar Elhami Khorasani>and then the amount of applied load, because the bottom floor is collecting load.

00:28:39.450 --> 00:28:43.400
<v Negar Elhami Khorasani>So you have, uh, you may have different utilization ratios for the column.

00:28:43.894 --> 00:28:46.815
<v Negar Elhami Khorasani>So going back to the load effect, it makes a difference.

00:28:47.275 --> 00:28:52.909
<v Negar Elhami Khorasani>And in the prescriptive approach, at least here in the us, it's not fully incorporated.

00:28:53.519 --> 00:28:56.788
<v Negar Elhami Khorasani>Uh, that effect of the, uh, load is not fully incorporated.

00:28:56.788 --> 00:29:05.618
<v Negar Elhami Khorasani>Therefore, you get various policies of failure across which may not be something we want to have, but it is what It, is

00:29:05.888 --> 00:29:08.912
<v Wojciech Węgrzyński>I mean, going just, the descriptive way.

00:29:08.912 --> 00:29:11.672
<v Wojciech Węgrzyński>You just have one , one safety, one assumed safety.

00:29:11.672 --> 00:29:16.152
<v Wojciech Węgrzyński>And it doesn't say that you, you're safer on the seventh floor versus, uh, on the second floor.

00:29:16.152 --> 00:29:18.672
<v Wojciech Węgrzyński>Well, it doesn't even explicitly say you are safe.

00:29:18.902 --> 00:29:20.711
<v Wojciech Węgrzyński>It's just we assume you are.

00:29:20.711 --> 00:29:21.711
<v Wojciech Węgrzyński>Once you follow that.

00:29:22.412 --> 00:29:23.372
<v Negar Elhami Khorasani>Yes, indeed.

00:29:23.442 --> 00:29:24.051
<v Negar Elhami Khorasani>Indeed.

00:29:24.382 --> 00:29:40.898
<v Negar Elhami Khorasani>So that's why, I mean, we are, we made an towards the end, I mean, that paper basically concluded that, we are not saying exactly as you, we are not saying that this is safe or not, we are not, Criticizing, let's say that the prescription or creating an alarm, that, uh, okay, people, this is not safe.

00:29:40.929 --> 00:29:51.739
<v Negar Elhami Khorasani>What, what we are advocating for is more harmonized safety, in a sense that if you set the safety level, let's make sure that we have that level of safety all across, even just one structure.

00:29:52.136 --> 00:29:58.017
<v Wojciech Węgrzyński>a, I'm a huge advocate of that, that type of thinking because I also believe we are spending a lot on safety.

00:29:58.436 --> 00:30:02.096
<v Wojciech Węgrzyński>I'm not saying we're spending too much on safety, but we, we are spending a lot.

00:30:02.116 --> 00:30:11.307
<v Wojciech Węgrzyński>And, uh, a huge chunk of a building coast goes into safety, especially pacifier safety, you know, uh, , even the, the concrete you add, uh, over your rebar.

00:30:11.307 --> 00:30:13.906
<v Wojciech Węgrzyński>So you protect them from, from being heated up.

00:30:14.557 --> 00:30:16.267
<v Wojciech Węgrzyński>Th these are the costs that add up.

00:30:16.487 --> 00:30:22.826
<v Wojciech Węgrzyński>And if there's a chance that this money could be spent in a better way to provide more safety, why not doing that?

00:30:23.096 --> 00:30:28.356
<v Wojciech Węgrzyński>Why spending it on stuff that does not matter when you could, uh, spend it money on stuff that matters.

00:30:29.017 --> 00:30:32.636
<v Wojciech Węgrzyński>But to know that you need to know that you need to calculate that.

00:30:32.636 --> 00:30:33.751
<v Wojciech Węgrzyński>And today we do not.

00:30:33.826 --> 00:30:34.497
<v Negar Elhami Khorasani>Exactly.

00:30:34.826 --> 00:30:35.497
<v Negar Elhami Khorasani>Exactly.

00:30:36.393 --> 00:30:36.883
<v Negar Elhami Khorasani>Okay.

00:30:36.883 --> 00:30:46.769
<v Negar Elhami Khorasani>So with the, the structural analysis box, after you quantify all your, you do your structural analysis using, again, choices up, up to the user.

00:30:46.769 --> 00:30:51.410
<v Negar Elhami Khorasani>You either use, um, finite element, uh, software level of complexity.

00:30:51.410 --> 00:30:52.210
<v Negar Elhami Khorasani>You go through that.

00:30:52.910 --> 00:31:04.200
<v Negar Elhami Khorasani>But what another important aspect is to decide how you want to characterize the response in a sense that what's coming out of that box Are the forces in your elements?

00:31:04.200 --> 00:31:07.559
<v Negar Elhami Khorasani>Is it the deflection, the formations in your elements?

00:31:08.170 --> 00:31:13.450
<v Negar Elhami Khorasani>Is it, for structural function, you can actually work with temperatures, you know, temperature in the rebar.

00:31:13.450 --> 00:31:14.009
<v Negar Elhami Khorasani>I don't know.

00:31:14.009 --> 00:31:16.369
<v Negar Elhami Khorasani>It's just the heat transfer part, so you have to.

00:31:16.744 --> 00:31:25.131
<v Negar Elhami Khorasani>Decide what, parameter or parameters you will be using to characterize, um, your structural response.

00:31:25.131 --> 00:31:31.691
<v Negar Elhami Khorasani>We call these within, I'm borrowing the terminology from earthquake engineering, but I've been using it the same for structural fire engine.

00:31:31.691 --> 00:31:33.931
<v Negar Elhami Khorasani>We call them engineering demand parameters.

00:31:34.430 --> 00:31:46.380
<v Negar Elhami Khorasani>So basically these are your demand parameters that move into the next box, which you will be using to quantify damage or fragility of the structure.

00:31:47.190 --> 00:31:48.470
<v Wojciech Węgrzyński>Let's let, let, let's go

00:31:48.640 --> 00:31:49.480
<v Negar Elhami Khorasani>Let's go there.

00:31:49.480 --> 00:31:49.839
<v Negar Elhami Khorasani>Okay.

00:31:50.289 --> 00:31:59.519
<v Negar Elhami Khorasani>So with the damage, the in simple, you know, terms, when I say fragility again, thinking about damage is, okay, you have a deformation.

00:32:00.250 --> 00:32:09.430
<v Negar Elhami Khorasani>that the formation, um, means what is the level of damage typically, we, Borrowing again from other fields.

00:32:09.440 --> 00:32:16.349
<v Negar Elhami Khorasani>We want to, uh, simplify the process in a way that, uh, you can communicate it easily.

00:32:16.599 --> 00:32:24.150
<v Negar Elhami Khorasani>So, uh, you could have categories, categories as in, um, slight damage, moderate damage, severe damage, and maybe.

00:32:24.825 --> 00:32:25.865
<v Negar Elhami Khorasani>almost near collapse.

00:32:26.555 --> 00:32:28.585
<v Negar Elhami Khorasani>So something like slight damage.

00:32:28.954 --> 00:32:34.904
<v Negar Elhami Khorasani>Uh, it later on maps to, you know, in next box it, it basically means it, it comes with definition.

00:32:34.904 --> 00:32:48.288
<v Negar Elhami Khorasani>So slight damage means, uh, you could potentially safe for your occupants to go back and inside the structure, and you don't have to spend much to repair.

00:32:48.758 --> 00:32:49.248
<v Negar Elhami Khorasani>Okay.

00:32:49.462 --> 00:32:52.962
<v Negar Elhami Khorasani>And it could be also even just cosmetic repair and something like that.

00:32:52.962 --> 00:32:55.282
<v Negar Elhami Khorasani>And then you move on to, you know, moderate damage.

00:32:55.792 --> 00:32:58.803
<v Negar Elhami Khorasani>Well, it means that maybe it's not safe, right?

00:32:59.103 --> 00:33:02.363
<v Negar Elhami Khorasani>For occupants to immediately go back, but it's repairable.

00:33:02.462 --> 00:33:04.482
<v Negar Elhami Khorasani>You don't have to necessarily demolish.

00:33:04.823 --> 00:33:10.965
<v Negar Elhami Khorasani>And then once you go into the severe or near collapse, then at that point, you are probably better off.

00:33:11.240 --> 00:33:17.000
<v Negar Elhami Khorasani>demolishing and rebuilding rather than repairing because it's too much, um, to repair.

00:33:17.188 --> 00:33:34.590
<v Wojciech Węgrzyński>Sorry, and, and again, this, this levels of damage is something you define for your particular building is not just, saying that the crack of this size or, or something, however you could define, is, is, is, is module damage is related to your structure in use is operations.

00:33:34.590 --> 00:33:34.911
<v Wojciech Węgrzyński>Right.

00:33:35.205 --> 00:33:35.726
<v Negar Elhami Khorasani>Right?

00:33:35.826 --> 00:33:36.246
<v Negar Elhami Khorasani>Yes.

00:33:36.403 --> 00:33:36.803
<v Negar Elhami Khorasani>true.

00:33:36.803 --> 00:33:40.202
<v Negar Elhami Khorasani>But it can be categorized for different structural systems.

00:33:40.813 --> 00:33:50.026
<v Negar Elhami Khorasani>So in a sense that ju you could basically lump things together for certain categories so that it gives guidance, for, again, the user.

00:33:50.026 --> 00:33:53.346
<v Negar Elhami Khorasani>So if somebody's using it, they don't have to start from basically scratch.

00:33:53.955 --> 00:34:00.906
<v Negar Elhami Khorasani>If you have a, steel frame with, um, a certain characteristic, maybe it's a.

00:34:00.906 --> 00:34:05.042
<v Negar Elhami Khorasani>Brace system and composite floor system and so on.

00:34:05.113 --> 00:34:12.402
<v Negar Elhami Khorasani>Then you define these categories for specifically for that and high rise, like higher than certain number of stories.

00:34:12.972 --> 00:34:17.420
<v Negar Elhami Khorasani>Uh, I am going to completely, put a twist here and just give an example.

00:34:18.340 --> 00:34:26.139
<v Negar Elhami Khorasani>Let's say, let's say now you've got a tunnel, because I've worked in that, you know, let's say now you've got a reinforced concrete, uh, tunnel, uh, liner.

00:34:26.597 --> 00:34:33.666
<v Negar Elhami Khorasani>you still, you can come up with these categories, uh, based on, the level of, I don't know, the crown, displacement.

00:34:33.666 --> 00:34:38.306
<v Negar Elhami Khorasani>That means okay, that probably at certain level of def formation, probably.

00:34:38.670 --> 00:34:46.141
<v Negar Elhami Khorasani>Certain crack widths, and that probably maps to a certain amount of repair requirements and so on.

00:34:46.471 --> 00:34:50.875
<v Negar Elhami Khorasani>Uh, so that goes in the category of tunnels and certain lining type.

00:34:51.324 --> 00:35:02.005
<v Negar Elhami Khorasani>So what we have actually in, in the seismic world, they have, invent inventories or databases of what they call fragility functions.

00:35:02.375 --> 00:35:02.864
<v Wojciech Węgrzyński>Okay.

00:35:03.159 --> 00:35:04.880
<v Negar Elhami Khorasani>and these fragility function.

00:35:05.610 --> 00:35:15.672
<v Negar Elhami Khorasani>are basically, developed for a suit of different structural types, structural elements, and they're all a function of, so it's important.

00:35:15.842 --> 00:35:23.833
<v Negar Elhami Khorasani>So on the X axis you have some sort of an intensity measure or the engineering demand parameter, right?

00:35:24.152 --> 00:35:26.913
<v Negar Elhami Khorasani>So that's where the engineering demand parameter comes into the picture.

00:35:27.253 --> 00:35:31.152
<v Negar Elhami Khorasani>You say, given this amount of deflection, what's the probability?

00:35:31.387 --> 00:35:32.668
<v Negar Elhami Khorasani>This is all probabilistic.

00:35:32.668 --> 00:35:37.668
<v Negar Elhami Khorasani>What's the probability of exceeding a certain damage state?

00:35:38.088 --> 00:35:43.507
<v Negar Elhami Khorasani>And those damage states are slight, moderate, severe, and you know, so on complete,

00:35:43.717 --> 00:35:57.838
<v Wojciech Węgrzyński>So instead of our, let's say L 30 criterion, uh, which is sometimes used or it's often used, you, you would now have a probability function that says, okay, with this level of deflection, the severities is this as it rises, it changes.

00:35:57.838 --> 00:35:58.318
<v Wojciech Węgrzyński>Okay.

00:35:58.603 --> 00:35:59.603
<v Negar Elhami Khorasani>Right, exactly.

00:35:59.663 --> 00:36:06.085
<v Negar Elhami Khorasani>And, you, it's again, what's important is that you pick an engineering demand parameter that reflects.

00:36:06.490 --> 00:36:07.474
<v Negar Elhami Khorasani>That level of damage.

00:36:07.485 --> 00:36:13.315
<v Negar Elhami Khorasani>So you can't just pick any, you, you, you want to make sure that it, it actually maps to that level of damage.

00:36:13.855 --> 00:36:17.478
<v Negar Elhami Khorasani>And then, the seismic ward, they use it the way that it happens.

00:36:17.478 --> 00:36:22.474
<v Negar Elhami Khorasani>That let's say you have this fragility functions for your, connections.

00:36:23.110 --> 00:36:28.199
<v Negar Elhami Khorasani>For your columns, for even, I'm gonna go even a step further.

00:36:28.199 --> 00:36:34.719
<v Negar Elhami Khorasani>They're trying, they're, they're not there yet, but they're trying to level all of these for non-structural components, Mm-hmm.

00:36:35.179 --> 00:36:35.739
<v Negar Elhami Khorasani>right?

00:36:36.070 --> 00:36:37.500
<v Negar Elhami Khorasani>Um, walls and so on.

00:36:37.750 --> 00:36:45.340
<v Negar Elhami Khorasani>So once you have your hazard, then they go to student structural analysis, then they end up with this third box.

00:36:45.603 --> 00:36:47.163
<v Negar Elhami Khorasani>the, the user doesn't have to do the,

00:36:47.994 --> 00:36:48.414
<v Wojciech Węgrzyński>Hmm.

00:36:48.750 --> 00:36:58.695
<v Negar Elhami Khorasani>that specific case, they go to these reference fragility functions and they start saying that, okay, now I know my deflection for, column or horizontal, you know, deflection.

00:36:58.766 --> 00:37:03.815
<v Negar Elhami Khorasani>I know the, some sort of parameter for temperature maybe in the connection and so on.

00:37:03.815 --> 00:37:20.280
<v Negar Elhami Khorasani>And then they look at, what would be the level of damage and then, Make a conclusion that this building, maybe you've got a component that's in damage state, slight, but you've got a key component that has reached, a severe damage state.

00:37:20.677 --> 00:37:24.900
<v Negar Elhami Khorasani>Then your pro, most likely, your structure overall is gonna be in the severe damage state.

00:37:25.240 --> 00:37:43.460
<v Wojciech Węgrzyński>So the user would go through the probabilistic analysis of the hazards, going through the iterating, through the scenarios, then going into the structural modeling, whatever model they choose, uh, to demine a certain, uh, parameter of their, of, of their structure, which they, they can compare with.

00:37:43.614 --> 00:37:51.324
<v Wojciech Węgrzyński>now a standardized or, or preproduced set of, Outcomes based on this value, they know the outcome would be like this.

00:37:51.554 --> 00:37:56.684
<v Wojciech Węgrzyński>It's severe, not severe, and, and based on the severity they can figure out what to do.

00:37:56.684 --> 00:37:58.804
<v Wojciech Węgrzyński>Well, I guess that's a step four when they go

00:37:58.869 --> 00:37:59.539
<v Negar Elhami Khorasani>Exactly.

00:37:59.539 --> 00:38:00.300
<v Negar Elhami Khorasani>That's exact.

00:38:00.300 --> 00:38:09.579
<v Negar Elhami Khorasani>So it's, it's, that's the part that, so as soon as you know, your dumb state, it maps to a repair cost and it maps to losses.

00:38:09.579 --> 00:38:13.655
<v Negar Elhami Khorasani>Now, those losses, it definitely can go beyond, uh, economic losses.

00:38:14.266 --> 00:38:19.590
<v Negar Elhami Khorasani>Um, you Potential for casualties, societal causes, social causes, you name it.

00:38:20.010 --> 00:38:22.635
<v Negar Elhami Khorasani>but, it makes a direct, connection there.

00:38:22.931 --> 00:38:33.920
<v Negar Elhami Khorasani>So what, uh, I would say within structural fire engineering, uh, the turret box, so I, I, I, I think fourth box is, um, more or less outside of my.

00:38:34.166 --> 00:38:34.775
<v Wojciech Węgrzyński>Mm-hmm.

00:38:34.925 --> 00:38:38.815
<v Negar Elhami Khorasani>Area because that again, brings in social aspects, economic aspects.

00:38:38.985 --> 00:38:47.670
<v Negar Elhami Khorasani>Uh, so the third box is where, perhaps I'm focusing on more now than the other boxes, because I've been working on the first box.

00:38:47.670 --> 00:38:48.630
<v Negar Elhami Khorasani>Then the second one.

00:38:48.679 --> 00:38:49.550
<v Negar Elhami Khorasani>So kind of moving.

00:38:49.550 --> 00:38:53.429
<v Negar Elhami Khorasani>Now I'm in the third box trying to quantify damage.

00:38:54.320 --> 00:38:55.519
<v Negar Elhami Khorasani>for certain structures.

00:38:55.519 --> 00:39:00.829
<v Negar Elhami Khorasani>And, one thing that in the past, two, three years, for example, we, we don't have the answers yet.

00:39:00.829 --> 00:39:16.862
<v Negar Elhami Khorasani>We are still working on it and I think it probably takes another few years, is again, that example of a tunnel, uh, lining reinforced concrete that I mentioned where okay, we, know that most likely won't collapse based on the analysis, but it's all about the down.

00:39:17.572 --> 00:39:24.905
<v Negar Elhami Khorasani>Of the tunnel because, especially again, in the US you may not have a redundant, route within the transportation network.

00:39:25.115 --> 00:39:33.025
<v Negar Elhami Khorasani>So if you shut down the tunnel because there was a fire, how long is it gonna take for the repair and quantifying the damage?

00:39:33.376 --> 00:39:37.023
<v Negar Elhami Khorasani>It's not as easy well, let's, let me put it this way.

00:39:37.976 --> 00:39:44.474
<v Negar Elhami Khorasani>we do not find a lot of literature and experimental, data on what happens after cooling.

00:39:45.393 --> 00:39:51.418
<v Negar Elhami Khorasani>if you are applying this, it's a structural fire engineering, you're not assuming, a standard fire, right?

00:39:51.717 --> 00:39:53.458
<v Negar Elhami Khorasani>You want to do this realistically.

00:39:53.458 --> 00:40:07.018
<v Negar Elhami Khorasani>So you have this cooling phase and you want to not only test during heating, but as well cooling and let it cool down until it's finds this new equilibrium and now measure, okay, what's the deflection?

00:40:07.768 --> 00:40:11.085
<v Negar Elhami Khorasani>What is the, locked in stresses and.

00:40:11.492 --> 00:40:13.612
<v Wojciech Węgrzyński>I love how you position it with tunnels.

00:40:13.612 --> 00:40:18.733
<v Wojciech Węgrzyński>Uh, what, what you're describing here is, is what, what we call here, resilience of the tunnel.

00:40:19.072 --> 00:40:24.893
<v Wojciech Węgrzyński>And I actually had an episode with an engineer from Switzerland Ingo Reiss about the resilience of tunnels.

00:40:25.702 --> 00:40:32.635
<v Wojciech Węgrzyński>He was focused more on the use of, of, uh, active fire protection in that you are focusing more on structural, performance of tunnels.

00:40:32.635 --> 00:40:39.115
<v Wojciech Węgrzyński>But, uh, in the end it's the, the same thing viewed from, uh, from the inside and from the mountain side of the, of the tunnel.

00:40:39.306 --> 00:40:44.556
<v Wojciech Węgrzyński>Very, very interesting how, how both, uh, worlds, uh, go, go through each other.

00:40:44.735 --> 00:40:48.219
<v Wojciech Węgrzyński>And I, I think that this is very, Interesting point of view.

00:40:48.590 --> 00:40:58.739
<v Wojciech Węgrzyński>It is kind of generic to say, oh, we need to, to understand our structures better, or we need better way to measure the damage, to take better informed decisions.

00:40:58.909 --> 00:41:13.056
<v Wojciech Węgrzyński>Of course we are that, that's kind of obvious, but I, I love how here you are, not just talking about it, we need that it is that you have a framework that can be adopted for that, a framework That allows you to work with it.

00:41:13.056 --> 00:41:15.815
<v Wojciech Węgrzyński>It's, it's, it's not a, a beautiful thought.

00:41:15.815 --> 00:41:18.096
<v Wojciech Węgrzyński>It's a tool, uh, that, that you present here.

00:41:18.346 --> 00:41:24.920
<v Wojciech Węgrzyński>So in, in the world of earthquake engineering, I guess there's, probably more than a hundred years of experience doing that.

00:41:25.090 --> 00:41:34.233
<v Wojciech Węgrzyński>Uh, so, so, Was this type of thinking, this type of framework in the world of earthquake engineering, did, did it go into the, the codes, into the low, into the standard?

00:41:34.652 --> 00:41:40.952
<v Wojciech Węgrzyński>How widely disused is it even possible to employ such a framework in, in, in the codified world we will live in?

00:41:41.175 --> 00:41:41.594
<v Negar Elhami Khorasani>yes.

00:41:41.594 --> 00:41:45.844
<v Negar Elhami Khorasani>So the, the earthquake engineering will definitely, um, it's more advanced.

00:41:45.934 --> 00:41:53.373
<v Negar Elhami Khorasani>So, and one of the perhaps, um, Would say wake up calls or what, what, what things, when things changed for them?

00:41:54.023 --> 00:42:01.699
<v Negar Elhami Khorasani>Uh, it was after, the, uh, 1994 Northridge Earth, earthquake, uh, in the US and California.

00:42:02.480 --> 00:42:17.315
<v Negar Elhami Khorasani>And, there were a number of, buildings did not perform as they had taught or wished, you know, for, so they started making really significant changes and right now at this stage, they performance based design.

00:42:17.315 --> 00:42:28.360
<v Negar Elhami Khorasani>You can definitely, Come up with many, many, many buildings, um, let's say in the, on the west coast of the US that they're built, uh, high-rise structures built using performance based design.

00:42:28.748 --> 00:42:43.695
<v Negar Elhami Khorasani>So one thing that I wanna mention is, Perhaps given that, again, it's uncertain and all the variability that you get and going through this procedure, it's not that you, if you follow performance-based design, you say that, okay?

00:42:44.306 --> 00:42:47.295
<v Negar Elhami Khorasani>Uh, with hundred percent certainty.

00:42:48.025 --> 00:42:53.795
<v Negar Elhami Khorasani>This is going to happen because still they don't know also and they acknowledge that.

00:42:54.186 --> 00:43:03.666
<v Negar Elhami Khorasani>and they also argue that maybe what they build necessarily, it's not, um, because they also have their own simplified or prescriptive approach that they can follow.

00:43:03.666 --> 00:43:05.025
<v Negar Elhami Khorasani>Nothing, you know, stops them.

00:43:05.735 --> 00:43:19.880
<v Negar Elhami Khorasani>the argument is they hope, and I believe this is true, I that using this approach, they are going to get buildings that perform, better or to the level that they have calculated.

00:43:20.010 --> 00:43:24.876
<v Negar Elhami Khorasani>So they get some sort we've used the term safety, that they're comfortable.

00:43:25.639 --> 00:43:49.059
<v Negar Elhami Khorasani>now, what they are moving, again, far from where we are and perhaps may not necessarily directly apply to structural fire engineering, but they have reached the level that they, uh, believe they've solved the collapse prevention problem in the sense that what they build is not going to collapse and they are really pushing for.

00:43:49.398 --> 00:43:50.621
<v Negar Elhami Khorasani>Immediate occupancy.

00:43:50.994 --> 00:43:53.074
<v Negar Elhami Khorasani>in a sense that nowadays say, okay.

00:43:53.695 --> 00:44:03.465
<v Negar Elhami Khorasani>a lot, a lot of that economic losses after an earthquake across a region is going to be because people cannot go back because of the downtime and everything.

00:44:03.465 --> 00:44:12.344
<v Negar Elhami Khorasani>And the downtime, I'm relating it to, again, to the tunnel project because that's the, the motivation there as a single structure versus many buildings across the region after an earthquake.

00:44:13.034 --> 00:44:26.735
<v Negar Elhami Khorasani>but, they think that, okay, now that we've solved collapse prevention, let's move on to, work on non-structured components and make sure that we can have occupants or minimize, the functional recovery, what they call.

00:44:26.735 --> 00:44:30.655
<v Negar Elhami Khorasani>So they want to be able to optimize that functional recovery.

00:44:31.155 --> 00:44:37.135
<v Negar Elhami Khorasani>Now, within fire engineering world, if you have a fire inside the building, no matter what, you still need to clean it up.

00:44:37.465 --> 00:44:44.094
<v Negar Elhami Khorasani>So in terms of the furniture, in terms of, again, non-structural components and things like that, so that directly doesn't map to what we do.

00:44:44.875 --> 00:45:14.925
<v Negar Elhami Khorasani>But if you really have a structure, that's critical, that has a certain, Uh, essential service that you want to be able to recover quickly, then you can at least work on the structural components from my perspective, structural engineering aspect of it, to make sure that you stay within that down state, one or two where you can repair it rather than you have to, basically demolish and.

00:45:15.411 --> 00:45:24.704
<v Wojciech Węgrzyński>I, I think in fire we are What's different from the earthquake is that the fire is localized even within your building, it doesn't necessarily affect the whole building.

00:45:24.704 --> 00:45:38.954
<v Wojciech Węgrzyński>And you, you may be quite okay with like, uh, let's say losing or, or having one fire compartment destroyed if your building is compartmentalized, but having the, the, the functionality of the rest of the building, and, uh, undisturbed.

00:45:39.494 --> 00:45:50.059
<v Wojciech Węgrzyński>And so, so, so like what you don't want to have is like, some sort of progressive collapse or, or some, some sort of, Damage to the hole that, that's in a way unnecessary.

00:45:50.309 --> 00:45:51.219
<v Wojciech Węgrzyński>In, in earthquake.

00:45:51.219 --> 00:45:53.739
<v Wojciech Węgrzyński>I guess it's an event that, that touches the whole building.

00:45:53.869 --> 00:45:58.739
<v Wojciech Węgrzyński>So if you have lightweight walls, it's gonna destroy them in every floor.

00:45:59.150 --> 00:46:05.213
<v Wojciech Węgrzyński>So, so you worried, worried more maybe on, on this aspect and in fire, we have ways to mitigate that.

00:46:05.619 --> 00:46:12.039
<v Wojciech Węgrzyński>But again, going back to, the thing that triggered this discussion, we don't know  how much we have.

00:46:12.250 --> 00:46:18.679
<v Wojciech Węgrzyński>We have absolutely no idea to what fire will cause, what sort of damage and what you propose.

00:46:18.679 --> 00:46:26.679
<v Wojciech Węgrzyński>Here is another way to, to look into that, that that could finally give us this answer that I believe we desperately need.

00:46:27.079 --> 00:46:32.969
<v Wojciech Węgrzyński>I also liked how, how you've placed it, you can build a catalog of of the losses.

00:46:33.065 --> 00:46:34.264
<v Negar Elhami Khorasani>Right, correct.

00:46:34.295 --> 00:46:43.824
<v Wojciech Węgrzyński>I, I think also like going, applying this methodology to some set of standardized or typical buildings can reveal their, um, functionality.

00:46:44.454 --> 00:46:56.128
<v Wojciech Węgrzyński>Even, you know, applying this method to, to, to structures, uh, That are codified, like following the, the, prescriptive codes could, could, uh, unravel their ultimate level of safety.

00:46:56.797 --> 00:46:59.128
<v Wojciech Węgrzyński>That would be funny thing to, to, to have.

00:46:59.338 --> 00:47:08.021
<v Wojciech Węgrzyński>So, so I really see a lot of implementation of frameworks, like, like the one that you've proposed and, for the end, to, to highlight the probabilistic aspect.

00:47:08.121 --> 00:47:13.460
<v Wojciech Węgrzyński>And in earthquake engineering, I assume they work with targets that are also tied to probabilities, right.

00:47:13.675 --> 00:47:14.496
<v Negar Elhami Khorasani>Yes, yes.

00:47:14.496 --> 00:47:19.969
<v Negar Elhami Khorasani>It's, you know, col, 2% probability of collapse for a, um, earthquake with a return period.

00:47:20.385 --> 00:47:21.755
<v Negar Elhami Khorasani>X, you know, such and such.

00:47:22.005 --> 00:47:31.019
<v Negar Elhami Khorasani>So, both of the terms, so the hazard return period, as well as, the chance of collapse, they're specified in a probabilistic term.

00:47:31.574 --> 00:47:45.030
<v Wojciech Węgrzyński>So the methodology starts probabilistic set of, uh, scenarios, likelihoods, uh, Which are ties to probabilistic, uh, ventilation factors, fuel load densities, all the aspects that drive the, the growth of the fire.

00:47:45.503 --> 00:47:49.123
<v Wojciech Węgrzyński>The loads on, on the building itself could be probabilistic.

00:47:49.123 --> 00:47:54.570
<v Wojciech Węgrzyński>Then you go through, Structural modeling with, uh, with, with some sort of, let's say conditional probabilities.

00:47:54.570 --> 00:48:05.186
<v Wojciech Węgrzyński>That, that scenarios that have certain probabilities that lead to certain engineering, uh, demand parameters that can translate into fragility damage and then losses.

00:48:05.376 --> 00:48:06.186
<v Wojciech Węgrzyński>I got it right.

00:48:06.186 --> 00:48:06.545
<v Wojciech Węgrzyński>I hope

00:48:06.721 --> 00:48:08.570
<v Negar Elhami Khorasani>Yeah, you definitely got it right.

00:48:08.570 --> 00:48:08.971
<v Negar Elhami Khorasani>Perfect.

00:48:09.431 --> 00:48:29.791
<v Negar Elhami Khorasani>The one thing I wanna mention quickly uh, another thing, that sort of, it's an assumption that goes into the, this procedure, but it works, is that you assume that the variables in this, analysis going from one box to another, uh, they're, from Pablo point of view, they're conditionally independent, right?

00:48:29.800 --> 00:48:30.911
<v Negar Elhami Khorasani>So when you're in one.

00:48:31.590 --> 00:48:34.360
<v Negar Elhami Khorasani>You're just in that box and you're not dependent.

00:48:34.501 --> 00:48:35.641
<v Negar Elhami Khorasani>You, you are dependent.

00:48:35.641 --> 00:48:40.440
<v Negar Elhami Khorasani>But in terms of, um, you can assume that, okay, given a hazard, now what?

00:48:40.670 --> 00:48:40.960
<v Negar Elhami Khorasani>I

00:48:41.121 --> 00:48:43.300
<v Wojciech Węgrzyński>you have a set of different branches

00:48:43.460 --> 00:48:43.880
<v Negar Elhami Khorasani>yes.

00:48:43.931 --> 00:48:55.887
<v Negar Elhami Khorasani>So you don't have a fee, like you don't have to go back and forth, but, which makes it easier for application in a sense that, you don't have to have to be an expert in all four boxes.

00:48:56.407 --> 00:48:56.967
<v Negar Elhami Khorasani>Right.

00:48:57.217 --> 00:48:59.288
<v Negar Elhami Khorasani>If you, you can rely on someone.

00:49:00.182 --> 00:49:02.983
<v Negar Elhami Khorasani>focus is on hazard analysis, right?

00:49:03.242 --> 00:49:09.302
<v Negar Elhami Khorasani>You say, here's your problem statement, here's the building or whatever the, the tunnel, whatever the structure is.

00:49:09.713 --> 00:49:16.146
<v Negar Elhami Khorasani>Uh, can you do me, a hazard analysis and give me a suit of, uh, potential scenarios?

00:49:16.735 --> 00:49:20.545
<v Negar Elhami Khorasani>Then maybe on the structural analysis, I really don't know.

00:49:20.655 --> 00:49:31.476
<v Negar Elhami Khorasani>I, I know how fire works because I'm a structural fine engineer and all of that, but, At the end of the day, I'm maybe not comfortable using a CFD or whatever, so I ask somebody else to do it, give me the output.

00:49:31.545 --> 00:49:33.115
<v Negar Elhami Khorasani>Then I use that as an input.

00:49:33.115 --> 00:49:43.396
<v Negar Elhami Khorasani>So breaking it up, even within that probabilistic approach, it, it gives you the opportunity to bring in experts where you need them in whatever box

00:49:43.931 --> 00:49:49.811
<v Wojciech Węgrzyński>and essentially what you need from them is, uh, an output plus, uh, probability of that output.

00:49:49.811 --> 00:49:51.251
<v Wojciech Węgrzyński>And, and then, then you're good.

00:49:51.490 --> 00:49:52.050
<v Wojciech Węgrzyński>Right?

00:49:52.275 --> 00:49:57.525
<v Wojciech Węgrzyński>I, I really enjoyed, I'm, I'm doing a lot of projects on wind and fire engineering at, at the moment.

00:49:57.835 --> 00:50:05.164
<v Wojciech Węgrzyński>I, I think in wind and fire it's a little more complicated because if you want to do it right, you have to, um, get the feedback, you know, like.

00:50:06.025 --> 00:50:11.585
<v Wojciech Węgrzyński>I cannot have a set of fires and then, uh, apply a set of winds to them because the wind will completely change the fire.

00:50:11.835 --> 00:50:16.648
<v Wojciech Węgrzyński>So, so wind and fire are now in my one box is a set of, of branches.

00:50:16.648 --> 00:50:19.688
<v Wojciech Węgrzyński>So every scenario is dictated by two probabilities.

00:50:19.708 --> 00:50:22.248
<v Wojciech Węgrzyński>One is the wind and the second is the fire.

00:50:22.248 --> 00:50:24.300
<v Wojciech Węgrzyński>But, the, the structure could, could be the same.

00:50:24.400 --> 00:50:32.940
<v Wojciech Węgrzyński>You are giving me a lot of ideas how to, how to structurize my, my thinking in this regard because if it's not structurized, it's not gonna.

00:50:33.365 --> 00:50:44.342
<v Negar Elhami Khorasani>Not to deviate, but just again, a parentheses because, uh, something that I've got involved recently is application of exactly these boxes and this framework to, communities and wildfire.

00:50:44.853 --> 00:50:45.342
<v Wojciech Węgrzyński>Okay.

00:50:45.577 --> 00:50:57.068
<v Negar Elhami Khorasani>Very different sort of problem because it's not, not just a single structure, now it's a community because it doesn't make sense for wildfires to have one structure that's wildfire proof because everything else will still get burned down.

00:50:57.471 --> 00:50:59.889
<v Negar Elhami Khorasani>but I'm thinking about wildfires.

00:50:59.958 --> 00:51:01.557
<v Negar Elhami Khorasani>uh, I just don't have the knowledge.

00:51:01.557 --> 00:51:08.438
<v Negar Elhami Khorasani>Maybe if I study, yes, but I do not have the knowledge to, uh, simulate wildfires in the white.

00:51:08.907 --> 00:51:16.695
<v Negar Elhami Khorasani>And you brought up the wind, which is pretty much, you know, wind modeling inside the community, outside the community is part of the problem.

00:51:17.130 --> 00:51:24.431
<v Negar Elhami Khorasani>But if somebody else gives me the wildfire scenario as its approaches the community, I can take that.

00:51:24.891 --> 00:51:29.175
<v Negar Elhami Khorasani>And then if somebody else gives me the windfield, in velocity over time.

00:51:29.324 --> 00:51:39.474
<v Negar Elhami Khorasani>I can also take that and then I can run my simulation, which is basically fire spread within the community and then move that into again, the damage box and so on.

00:51:39.885 --> 00:51:45.394
<v Negar Elhami Khorasani>So, again, same sort of thinking, uh, and framework Now, a completely different.

00:51:45.721 --> 00:51:47.831
<v Wojciech Węgrzyński>Uh, that's what I love about fire science.

00:51:47.831 --> 00:51:51.431
<v Wojciech Węgrzyński>There is no, unrelated, you know, topics to discuss.

00:51:51.815 --> 00:51:56.684
<v Wojciech Węgrzyński>what has been, uh, 40 something minutes of discussion on structural fire engineering.

00:51:56.905 --> 00:52:06.364
<v Wojciech Węgrzyński>Now with this one tiny twist, someone who's doing wildfire research can say, oh, okay, that's, uh, that's directly applicable to them and it's directly applicable to my wind engineering studies.

00:52:06.934 --> 00:52:08.405
<v Wojciech Węgrzyński>So, , thank you very much.

00:52:08.405 --> 00:52:11.844
<v Wojciech Węgrzyński>That has been a very useful, I, I really enjoyed this.

00:52:11.844 --> 00:52:13.644
<v Wojciech Węgrzyński>I, I, I love the structure.

00:52:13.644 --> 00:52:15.844
<v Wojciech Węgrzyński>I love the, how it is a framework.

00:52:15.844 --> 00:52:17.605
<v Wojciech Węgrzyński>It's not, uh, nice thought.

00:52:17.605 --> 00:52:18.085
<v Wojciech Węgrzyński>It's not.

00:52:18.478 --> 00:52:19.744
<v Wojciech Węgrzyński>philosophical discussion.

00:52:19.744 --> 00:52:20.545
<v Wojciech Węgrzyński>It is a tool.

00:52:20.954 --> 00:52:24.088
<v Wojciech Węgrzyński>Uh, I didn't know it is a tool before this discussion.

00:52:24.088 --> 00:52:27.168
<v Wojciech Węgrzyński>So I'm very happy you've helped me discover it is a tool.

00:52:27.701 --> 00:52:29.380
<v Wojciech Węgrzyński>so I, I guess that's it.

00:52:29.431 --> 00:52:32.621
<v Wojciech Węgrzyński>Uh, now for the, before We Pathways, uh, maybe.

00:52:33.365 --> 00:52:39.195
<v Wojciech Węgrzyński>If someone would like to learn more about that, any resources you could recommend to, to learn more?

00:52:39.195 --> 00:52:47.028
<v Wojciech Węgrzyński>I'm gonna link the, the fuel load paper in, in the, in the show notes and the review of, practice to the lift load modeling.

00:52:47.028 --> 00:52:47.949
<v Wojciech Węgrzyński>Maybe they're small.

00:52:48.548 --> 00:52:48.969
<v Negar Elhami Khorasani>yes.

00:52:49.018 --> 00:52:51.976
<v Negar Elhami Khorasani>Uh, we do papers on as well on material models.

00:52:52.541 --> 00:52:55.072
<v Negar Elhami Khorasani>I can definitely, uh, send them to you.

00:52:55.302 --> 00:53:02.711
<v Negar Elhami Khorasani>I do want to, uh, actually, because the very first paper on the topic.

00:53:03.672 --> 00:53:15.436
<v Negar Elhami Khorasani>Which again adopts the idea from, um, earthquake Engineering is actually by, uh, professor David Lange and Professor Asif Usmani and, Dr.

00:53:15.505 --> 00:53:27.726
<v Negar Elhami Khorasani>Sean, Deney, and the, if I'm not mistaken, the, the title of the paper was an application of the Peer Performance Based Engineering Framework, two Structures in Fire that goes back in 2014.

00:53:28.195 --> 00:53:32.851
<v Negar Elhami Khorasani>So, it, it basically lays out, you know, these steps, right?

00:53:32.851 --> 00:53:38.612
<v Negar Elhami Khorasani>The way that I, I describe 'em as boxes, but they have like a figure and they say, okay, you go from here to here, and so on.

00:53:39.141 --> 00:53:47.565
<v Negar Elhami Khorasani>So I, I'll definitely send you that paper as well because that, uh, within, I think our community does set the tone, for this procedure.

00:53:48.266 --> 00:53:50.925
<v Negar Elhami Khorasani>And, um, I'll take a look at my publications.

00:53:50.925 --> 00:53:52.766
<v Negar Elhami Khorasani>If there's anything relevant, I'll send it.

00:53:53.286 --> 00:53:53.965
<v Wojciech Węgrzyński>Fantastic.

00:53:53.965 --> 00:54:03.556
<v Wojciech Węgrzyński>And I also had an, actually, as you mentioned, David, I had an episode with David, David and, and, EZ, who was, uh, doing maximal damage, method.

00:54:03.606 --> 00:54:07.115
<v Wojciech Węgrzyński>Uh, so I guess they, they covered the fourth box with the losses.

00:54:07.115 --> 00:54:07.596
<v Wojciech Węgrzyński>Uh, yeah.

00:54:07.596 --> 00:54:08.235
<v Wojciech Węgrzyński>Fantastic.

00:54:08.646 --> 00:54:10.436
<v Wojciech Węgrzyński>So all, all of it ties together.

00:54:10.922 --> 00:54:13.722
<v Wojciech Węgrzyński>Super thankful for, for this interview.

00:54:13.871 --> 00:54:15.762
<v Wojciech Węgrzyński>I hope people found it interesting.

00:54:16.072 --> 00:54:18.402
<v Wojciech Węgrzyński>It's advanced structural fire engineering.

00:54:18.472 --> 00:54:23.442
<v Wojciech Węgrzyński>I know in many places we're not there yet, even with, uh, with just structural fire engineering.

00:54:23.628 --> 00:54:31.878
<v Wojciech Węgrzyński>I think that's, that's a very promising future and it's, it's fantastic to learn what you can achieve and what you can do with, uh, with these advanced methods.

00:54:32.168 --> 00:54:34.818
<v Wojciech Węgrzyński>So, Someone chooses to, to go for them.

00:54:34.818 --> 00:54:40.778
<v Wojciech Węgrzyński>They have a better understanding of what they get, what the benefits are, and uh, what it can bring to a project.

00:54:40.789 --> 00:54:42.885
<v Wojciech Węgrzyński>So Nagar, thank you very much for this.

00:54:42.885 --> 00:54:44.525
<v Wojciech Węgrzyński>It was a fantastic, uh, talking

00:54:44.530 --> 00:54:45.210
<v Negar Elhami Khorasani>Thank you.

00:54:45.210 --> 00:54:46.331
<v Negar Elhami Khorasani>so much for having me.

00:54:46.460 --> 00:54:49.233
<v Negar Elhami Khorasani>Uh, it was, great, being here on this podcast.

00:54:49.534 --> 00:54:51.034
<v Negar Elhami Khorasani>And just a final note.

00:54:51.351 --> 00:54:55.170
<v Negar Elhami Khorasani>I'm teaching course on Structures and Fire here.

00:54:55.380 --> 00:54:55.891
<v Negar Elhami Khorasani>Um, at.

00:54:56.141 --> 00:54:56.581
<v Negar Elhami Khorasani>Buffalo.

00:54:57.280 --> 00:55:00.981
<v Negar Elhami Khorasani>And, uh, as part of the course, you know, the students have a project.

00:55:01.331 --> 00:55:17.860
<v Negar Elhami Khorasani>They have to do case studies and read about it and come back and, you know, and, I'll be assigning, uh, not my own podcast, other podcast, the, the other ones I'm going to assign them to, uh, listen to your podcast and come back and provide summaries and things they've learned from the podcast.

00:55:18.510 --> 00:55:19.860
<v Negar Elhami Khorasani>So, thank you for doing this.

00:55:19.960 --> 00:55:24.780
<v Negar Elhami Khorasani>You, you are contributing to even, you know, our, uh, my students here at ub.

00:55:24.795 --> 00:55:25.583
<v Wojciech Węgrzyński>Fantastic.

00:55:25.619 --> 00:55:28.259
<v Wojciech Węgrzyński>I hope they enjoy it and, and get something out of it.

00:55:28.349 --> 00:55:32.059
<v Wojciech Węgrzyński>If they don't let me know, that means I have to get a new episode coming.

00:55:33.318 --> 00:55:34.329
<v Negar Elhami Khorasani>Noah, thank you so

00:55:34.478 --> 00:55:35.088
<v Wojciech Węgrzyński>Thanks.

00:55:35.088 --> 00:55:35.568
<v Wojciech Węgrzyński>Cheers.

00:55:36.103 --> 00:55:39.402
<v Wojciech Węgrzyński>And is it as promised a little bit complicated.

00:55:39.672 --> 00:55:41.143
<v Wojciech Węgrzyński>Maybe a little bit difficult.

00:55:41.443 --> 00:55:48.583
<v Wojciech Węgrzyński>Definitely a step up from just structural fire engineering, but very natural concept in the end.

00:55:48.583 --> 00:55:50.773
<v Wojciech Węgrzyński>If you think about the nature of fires.

00:55:51.193 --> 00:55:55.452
<v Wojciech Węgrzyński>And the nature of safety to view this true probabilities scenarios.

00:55:55.992 --> 00:56:01.663
<v Wojciech Węgrzyński>Uh, damage and in the end of the possible loss, that can be the result of the damage.

00:56:02.083 --> 00:56:08.211
<v Wojciech Węgrzyński>So I believe this a probabilistic framework Negar can be applied to many places in far engineering.

00:56:08.242 --> 00:56:16.461
<v Wojciech Węgrzyński>Like in the end of the podcast episode, we discussed how she's applying that to wildfire communities and wildfire preparedness.

00:56:16.461 --> 00:56:17.811
<v Wojciech Węgrzyński>I believe that's brilliant.

00:56:18.172 --> 00:56:20.331
<v Wojciech Węgrzyński>I already see how I can apply this.

00:56:20.371 --> 00:56:23.822
<v Wojciech Węgrzyński>To my wind and fire coupled modeling.

00:56:23.882 --> 00:56:24.302
<v Wojciech Węgrzyński>So.

00:56:24.807 --> 00:56:27.958
<v Wojciech Węgrzyński>I really enjoyed listening about this too.

00:56:28.108 --> 00:56:36.717
<v Wojciech Węgrzyński>I must say I've never heard about this approach or this structure of an approach to probabilistic, fire engineering.

00:56:36.748 --> 00:56:37.887
<v Wojciech Węgrzyński>And I'm very happy.

00:56:37.887 --> 00:56:38.757
<v Wojciech Węgrzyński>I did learn it.

00:56:39.208 --> 00:56:43.978
<v Wojciech Węgrzyński>And I hope some of you have learned something new along me today.

00:56:44.637 --> 00:56:48.297
<v Wojciech Węgrzyński>Thank you very much for listening to the today's episode.

00:56:48.655 --> 00:56:52.704
<v Wojciech Węgrzyński>As I've mentioned in the intro to this episode, they see lots of new people in the podcast.

00:56:52.704 --> 00:56:54.860
<v Wojciech Węgrzyński>AC a lot of of listeners around.

00:56:55.101 --> 00:57:05.331
<v Wojciech Węgrzyński>So, uh, let me take this opportunity to ask you for leaving me some five star reviews on Apple Podcast, Spotify, or you can leave a review directly on my webpage.

00:57:05.541 --> 00:57:12.889
<v Wojciech Węgrzyński>These reviews are tremendously helpful to the growth of the podcast because they heavily influenced the search algorithms.

00:57:13.280 --> 00:57:17.059
<v Wojciech Węgrzyński>In the internet and as, you know, search rules, everything.

00:57:17.059 --> 00:57:17.420
<v Wojciech Węgrzyński>So.

00:57:17.692 --> 00:57:19.192
<v Wojciech Węgrzyński>By leaving me a review.

00:57:19.251 --> 00:57:26.061
<v Wojciech Węgrzyński>You're highly improving somebody's chance to stumble upon this, uh, this show that may be useful to them.

00:57:26.362 --> 00:57:27.052
<v Wojciech Węgrzyński>I hope that.

00:57:27.411 --> 00:57:29.331
<v Wojciech Węgrzyński>And, uh, also.

00:57:29.530 --> 00:57:35.018
<v Wojciech Węgrzyński>As I've noticed through my serve you well of mouth is number one tool to grow the podcast.

00:57:35.018 --> 00:57:42.907
<v Wojciech Węgrzyński>So if you can pass the knowledge about this podcast to your friends and colleagues, I will certainly appreciate that.

00:57:43.159 --> 00:57:46.789
<v Wojciech Węgrzyński>Because that helps me affect more engineers worldwide.

00:57:46.789 --> 00:57:49.068
<v Wojciech Węgrzyński>And that's some sort of my goal.

00:57:49.128 --> 00:57:51.858
<v Wojciech Węgrzyński>So thank you very much for sharing the podcast.

00:57:52.159 --> 00:57:54.199
<v Wojciech Węgrzyński>If you find it useful, please do so.

00:57:54.798 --> 00:57:57.438
<v Wojciech Węgrzyński>And that's it for today's episode.

00:57:57.469 --> 00:58:00.139
<v Wojciech Węgrzyński>Thank you for the great month of January.

00:58:00.619 --> 00:58:04.068
<v Wojciech Węgrzyński>I'm still looking for questions for Q and a of January.

00:58:04.068 --> 00:58:05.268
<v Wojciech Węgrzyński>I don't have too many.

00:58:05.568 --> 00:58:09.048
<v Wojciech Węgrzyński>So if you wish to ask me questions, please do so.

00:58:09.378 --> 00:58:19.548
<v Wojciech Węgrzyński>Uh, you can do that through the SpeakPipe on the website, or you can send me an email and I'll try to answer that or find someone who can answer that on my behalf.

00:58:19.750 --> 00:58:25.030
<v Wojciech Węgrzyński>The Q and a episode will be published more or less after 8th of February.

00:58:25.436 --> 00:58:26.726
<v Wojciech Węgrzyński>That's not a coincidence.

00:58:26.757 --> 00:58:30.536
<v Wojciech Węgrzyński>8th of February is the deadline for IFSS paper submission.

00:58:30.567 --> 00:58:36.056
<v Wojciech Węgrzyński>So if you're a fire scientist, I guess you have a very similar deadline as I do.

00:58:36.507 --> 00:58:38.097
<v Wojciech Węgrzyński>In this regard anyways.

00:58:38.817 --> 00:58:40.016
<v Wojciech Węgrzyński>Thank you very much for being here.

00:58:40.077 --> 00:58:41.606
<v Wojciech Węgrzyński>See you here next Wednesday.

00:58:41.697 --> 00:58:42.237
<v Wojciech Węgrzyński>Cheers.