T. Nakao, A. Yanagisawa, Akihide Jo, K. Wakatsuki, Y. Ohmiya
{"title":"Fire Plume Ejected from an Opening in Unconfined Space Part 1 Experimental Outline","authors":"T. Nakao, A. Yanagisawa, Akihide Jo, K. Wakatsuki, Y. Ohmiya","doi":"10.3210/FST.26.497","DOIUrl":"https://doi.org/10.3210/FST.26.497","url":null,"abstract":"","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83951119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It’s a great pleasure to be here today and a great honor to present a little about what is going on in fire research in Europe. I’d like to speak first about fire regulations because this is most important if you want to use fire safety engineering. One important aspect is natural fires, since they differ from standard fires, and then I will speak about structural fire design especially with regards to the robustness of safety measures. I will then present some research topics as Dr Osaki asked, and I’ll talk a little about Eurocodes. Now, in terms of fire regulations, there are different concepts; performance-based concepts and prescriptive concepts. With prescriptive concepts, still mostly used in Europe, design is easy. You just open the book and do what it says. However, it offers little flexibility and it may be quite expensive for steel structures. With performance-based design, you only get objective based regulation and then you make the design. The problem is that you have to go to the authorities and discuss it and get it accepted. So may be you do a design and after 6 months you find out they don’ t want to accept it. So although you have a lot of flexibility, you also have the risk that acceptance will take a long time. Therefore, in Swiss regulation, we have introduced something in between. We give free choice between different concepts. Either you go with the traditional structural concept with structural fire resistance or you add a Figure 2.2.1
{"title":"Fire Engineering of Buildings-Some Aspects on the Situation in Switzerland and EuropeRecent Research at ETH Zurich","authors":"M. Fontana","doi":"10.3210/FST.26.67","DOIUrl":"https://doi.org/10.3210/FST.26.67","url":null,"abstract":"It’s a great pleasure to be here today and a great honor to present a little about what is going on in fire research in Europe. I’d like to speak first about fire regulations because this is most important if you want to use fire safety engineering. One important aspect is natural fires, since they differ from standard fires, and then I will speak about structural fire design especially with regards to the robustness of safety measures. I will then present some research topics as Dr Osaki asked, and I’ll talk a little about Eurocodes. Now, in terms of fire regulations, there are different concepts; performance-based concepts and prescriptive concepts. With prescriptive concepts, still mostly used in Europe, design is easy. You just open the book and do what it says. However, it offers little flexibility and it may be quite expensive for steel structures. With performance-based design, you only get objective based regulation and then you make the design. The problem is that you have to go to the authorities and discuss it and get it accepted. So may be you do a design and after 6 months you find out they don’ t want to accept it. So although you have a lot of flexibility, you also have the risk that acceptance will take a long time. Therefore, in Swiss regulation, we have introduced something in between. We give free choice between different concepts. Either you go with the traditional structural concept with structural fire resistance or you add a Figure 2.2.1","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88337611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When a fire emerges inside a building, the windows break, flames and smoke eject outside, and there is a risk that the fire will spread to upper floors and neighboring buildings. Installing a soffit at the upper edge of any openings has been proposed as the first measure against spreading fire to upper floors. In this respect, the purpose of this research is to understand the quantitative aspects of a fire plume ejected through an opening by performing an experiment using a compartment model.
{"title":"Behavior of Fire Plume Ejected from Opening with Soffit","authors":"A. Yanagisawa, Y. Ohmiya","doi":"10.3210/FST.26.529","DOIUrl":"https://doi.org/10.3210/FST.26.529","url":null,"abstract":"When a fire emerges inside a building, the windows break, flames and smoke eject outside, and there is a risk that the fire will spread to upper floors and neighboring buildings. Installing a soffit at the upper edge of any openings has been proposed as the first measure against spreading fire to upper floors. In this respect, the purpose of this research is to understand the quantitative aspects of a fire plume ejected through an opening by performing an experiment using a compartment model.","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81121253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Today I make a presentation on the redundancy and stress redistribution of rigidly connected steel frames subject to fire. Stress redistribution is a main theme of this presentation. Redundancy has the same meaning. I will take rigidly connected steel structures, since a majority of structures are designed to be rigidly connected in Japan to increase both rigidity and strength for seismic design. A rigidly connected frame indicates, of course, a frame with moment connections. In such frames, when they are overloaded, local plastification and subsequent sound stress redistribution often occurs without loss of strength. The situation is similar when they are subjected to fire. I would like to present my recent research, and my talk will be quite brief and simple. The more refined, more specific details and discussions, I’ll leave to my colleague Dr. Jun-ichi Suzuki. Now I discuss three typical examples of stress redistribution that can be often observed in heated frames. About the first and second examples you probably know well: the first example is stress redistribution that occurs in plastified beams and the second example is stress redistribution that occurs in plastified columns. The third example is probably a new topic to you. This involves the overall stress redistribution that occurs in a whole heated frame subsequent to column buckling. The phenomenon may be similar to local buckling of a plate in that, as Dr. Knobloch pointed out, post-local buckling behavior of a plate remains stable if sound stress redistribution works after the onset of buckling. Here you can see stress redistribution created in plastified beams as shown in Figure 2.3.3. This is a T-shaped frame—the left half of a symmetrical frame and we assume the lower column and the beam are equally heated. When the member temperature is elevated, the beam is plastified first since beam load is assumed to be large. The Fire Science and Technology Vol.26 No.2(2007) 87-92 87
{"title":"Redundancy and Stress Redistribution of Rigidly Connected Steel Frames subject to Fire","authors":"Hiroyuki Suzuki","doi":"10.3210/FST.26.87","DOIUrl":"https://doi.org/10.3210/FST.26.87","url":null,"abstract":"Today I make a presentation on the redundancy and stress redistribution of rigidly connected steel frames subject to fire. Stress redistribution is a main theme of this presentation. Redundancy has the same meaning. I will take rigidly connected steel structures, since a majority of structures are designed to be rigidly connected in Japan to increase both rigidity and strength for seismic design. A rigidly connected frame indicates, of course, a frame with moment connections. In such frames, when they are overloaded, local plastification and subsequent sound stress redistribution often occurs without loss of strength. The situation is similar when they are subjected to fire. I would like to present my recent research, and my talk will be quite brief and simple. The more refined, more specific details and discussions, I’ll leave to my colleague Dr. Jun-ichi Suzuki. Now I discuss three typical examples of stress redistribution that can be often observed in heated frames. About the first and second examples you probably know well: the first example is stress redistribution that occurs in plastified beams and the second example is stress redistribution that occurs in plastified columns. The third example is probably a new topic to you. This involves the overall stress redistribution that occurs in a whole heated frame subsequent to column buckling. The phenomenon may be similar to local buckling of a plate in that, as Dr. Knobloch pointed out, post-local buckling behavior of a plate remains stable if sound stress redistribution works after the onset of buckling. Here you can see stress redistribution created in plastified beams as shown in Figure 2.3.3. This is a T-shaped frame—the left half of a symmetrical frame and we assume the lower column and the beam are equally heated. When the member temperature is elevated, the beam is plastified first since beam load is assumed to be large. The Fire Science and Technology Vol.26 No.2(2007) 87-92 87","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77973824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A correlation of flame heights is presented for recent experiments of merging group fires produced from arrays of gaseous burners. The correlation is based on two considerations: a) the air entrainment up to the flame height is proportional to the stoichiometric requirements for combustion of the fuel and b)the air entrained is equal to the side area of the plume multiplied by an entrainment velocity proportional to the square root of the vertical distance from the source. This correlation is applicable for an array of merging fires as recent results verify. Justification for merging of the investigated group fires is given together with comparison with older work.
{"title":"A Correlation for the Flame Height in \"Group\" Fires","authors":"M. Delichatsios","doi":"10.3210/FST.26.1","DOIUrl":"https://doi.org/10.3210/FST.26.1","url":null,"abstract":"A correlation of flame heights is presented for recent experiments of merging group fires produced from arrays of gaseous burners. The correlation is based on two considerations: a) the air entrainment up to the flame height is proportional to the stoichiometric requirements for combustion of the fuel and b)the air entrained is equal to the side area of the plume multiplied by an entrainment velocity proportional to the square root of the vertical distance from the source. This correlation is applicable for an array of merging fires as recent results verify. Justification for merging of the investigated group fires is given together with comparison with older work.","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84607489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Takahiro Ishihara, H. Sunahara, Akimitsu Kikkawa, M. Mizuno, Y. Ohmiya, M. Morita
Heat transfer to structural members is a principal factor in a building fire. Various theoretical and experimental studies have been undertaken with respect to the flame and flame length in order to estimate the heat input. The properties of a flame that grows in the vertical direction have been revealed by many researchers that commonly use fire steadily ignited by a burner; however, there is little research that considers a flame spreading horizontally to a ceiling as a result of a growing fire.[2] In a steadily burning fire that heats the ceiling until the flame length becomes stable, it can be expected that the accumulated heat on the ceiling influences the flame length. Therefore, in this experiment, the flame height with respect to the developing fire was investigated by using a wood crib that replicates a growing fire in the actual fire. The relation of the burning rate and the flame length with respect to a temporally developing fire can be obtained by measuring the flame length with a time-variable scale of the fire.
{"title":"Fire Behavior under a Ceiling in Growing Fire Part 2 Ceiling Jet Velocity and Flame Length","authors":"Takahiro Ishihara, H. Sunahara, Akimitsu Kikkawa, M. Mizuno, Y. Ohmiya, M. Morita","doi":"10.3210/FST.26.479","DOIUrl":"https://doi.org/10.3210/FST.26.479","url":null,"abstract":"Heat transfer to structural members is a principal factor in a building fire. Various theoretical and experimental studies have been undertaken with respect to the flame and flame length in order to estimate the heat input. The properties of a flame that grows in the vertical direction have been revealed by many researchers that commonly use fire steadily ignited by a burner; however, there is little research that considers a flame spreading horizontally to a ceiling as a result of a growing fire.[2] In a steadily burning fire that heats the ceiling until the flame length becomes stable, it can be expected that the accumulated heat on the ceiling influences the flame length. Therefore, in this experiment, the flame height with respect to the developing fire was investigated by using a wood crib that replicates a growing fire in the actual fire. The relation of the burning rate and the flame length with respect to a temporally developing fire can be obtained by measuring the flame length with a time-variable scale of the fire.","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83193992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Wakamatsu, Seiji Okinaga, M. Mizuno, T. Wakamatsu
As shown in Figure 1, the initial condition of the method was that the heating temperature T0 (fire room) was 20°C and the temperatures of the gaps inside the steel tubes (T3 and T6 ) were 20°C. The coefficients of heat transfer H1 , H2 , H3 , H4 and H5 (W/m2K) were given as follows. Here, H1 , H2 , H3 and H4 were the coefficients of heat transfer for the external surface of the outside steel tube, the internal surface of the outside steel tube, the external surface of the inside steel tube and the internal surface of the inside steel tube respectively. And H5 was the coefficients of radiative heat transfer between the internal surface of the outside steel tube and the external surface of the internal surface of the inside steel tube.
{"title":"Heating Mechanism of Double Tubular Steel Columns Part 2 Numerical Analysis and Comparison with the Experimental Results","authors":"T. Wakamatsu, Seiji Okinaga, M. Mizuno, T. Wakamatsu","doi":"10.3210/FST.26.321","DOIUrl":"https://doi.org/10.3210/FST.26.321","url":null,"abstract":"As shown in Figure 1, the initial condition of the method was that the heating temperature T0 (fire room) was 20°C and the temperatures of the gaps inside the steel tubes (T3 and T6 ) were 20°C. The coefficients of heat transfer H1 , H2 , H3 , H4 and H5 (W/m2K) were given as follows. Here, H1 , H2 , H3 and H4 were the coefficients of heat transfer for the external surface of the outside steel tube, the internal surface of the outside steel tube, the external surface of the inside steel tube and the internal surface of the inside steel tube respectively. And H5 was the coefficients of radiative heat transfer between the internal surface of the outside steel tube and the external surface of the internal surface of the inside steel tube.","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81892944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akihide Jo, T. Nakao, A. Yanagisawa, K. Wakatsuki, Y. Ohmiya
{"title":"Fire Plume Ejected from an Opening in Unconfined Space Part 3 Behavior of Fire Plume Ejected from an Opening in the Vicinity of Opposed Walls","authors":"Akihide Jo, T. Nakao, A. Yanagisawa, K. Wakatsuki, Y. Ohmiya","doi":"10.3210/FST.26.511","DOIUrl":"https://doi.org/10.3210/FST.26.511","url":null,"abstract":"","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86534901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mitsuru Ota, J. Yamaguchi, Yuta Kuwana, Yoshihumi Ohmiya
In Japan, it is required by law to install a sprinkler system (hereafter, SP System) in accordance with the use of the building and its size. In general, the purpose of the SP System is to extinguish fires, and therefore most research reports are related to fire extinguishing. However, the influence of the SP system activation on the smoke layer has not yet been sufficiently assessed. It is difficult to quantify the extinguishing time for SP systems, and the prediction of the behavior of the flames and the smoke, which is restricted by the SP systems, is still in the process of preliminary research. In order to be able to apply the influence of fire extinguishing equipment on the smoke behavior to the performance design, the effects of the sprinkling system need to be quantified. The successful evaluation and application of the fire suppression effects would allow for a more rational assessment of the fire performance, which is currently evaluated by assuming the emergence of an uncontrolled fire. Consequently, this would result in greater flexibility with respect to fire prevention planning Therefore, this experimental study examined the influence on the smoke layer during sprinkling, in order to obtain information about smoke behavior during the SP system activation. In this paper, the changes occurring in the fire plume after sprinkling are reported.
{"title":"A Study of Smoke Behavior in a Compartment with Sprinkler System Activation -Theory and Validity on the Flow Rate of the Fire Plume during Sprinkler System Activation-","authors":"Mitsuru Ota, J. Yamaguchi, Yuta Kuwana, Yoshihumi Ohmiya","doi":"10.3210/FST.26.551","DOIUrl":"https://doi.org/10.3210/FST.26.551","url":null,"abstract":"In Japan, it is required by law to install a sprinkler system (hereafter, SP System) in accordance with the use of the building and its size. In general, the purpose of the SP System is to extinguish fires, and therefore most research reports are related to fire extinguishing. However, the influence of the SP system activation on the smoke layer has not yet been sufficiently assessed. It is difficult to quantify the extinguishing time for SP systems, and the prediction of the behavior of the flames and the smoke, which is restricted by the SP systems, is still in the process of preliminary research. In order to be able to apply the influence of fire extinguishing equipment on the smoke behavior to the performance design, the effects of the sprinkling system need to be quantified. The successful evaluation and application of the fire suppression effects would allow for a more rational assessment of the fire performance, which is currently evaluated by assuming the emergence of an uncontrolled fire. Consequently, this would result in greater flexibility with respect to fire prevention planning Therefore, this experimental study examined the influence on the smoke layer during sprinkling, in order to obtain information about smoke behavior during the SP system activation. In this paper, the changes occurring in the fire plume after sprinkling are reported.","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88386831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C h a n g e s i n b u i l d i n g s y s t e m s a n d developments in architectural technology have become larger in scope and have led to taller and more complex buildings. These developments have also resulted in an increase of potential risks associated with building fires. During the past several decades, the construction of tall buildings has been booming in Korea. However, the fire safety design for buildings has not been properly established to catch up to these demands, and fire losses are increasing. It is essential to understand that fire safety engineering cannot prosper alone, and it is not even enough to be supported by research in that specific area. Fundamental research requires support from other disciplines and from multidisciplinary research groups. Performance-based design is becoming more common as facilities incorporate unique features to achieve aesthetic, cost and functional goals while maintaining safety levels for building occupants and emergency responders. Performance-based design allows for significant design flexibility; however, therein lies a great responsibility to maintain fire protection features that might go beyond those required by code. Without knowledge of the mitigating features, a well-intentioned contractor or designer could compromise the building's safety during future renovations.
{"title":"An Overview of the Current Fire Research and Fire Safety Design in Korea","authors":"Sangdae Kim, M. Kim, Seong-Deok Kang","doi":"10.3210/FST.26.43","DOIUrl":"https://doi.org/10.3210/FST.26.43","url":null,"abstract":"C h a n g e s i n b u i l d i n g s y s t e m s a n d developments in architectural technology have become larger in scope and have led to taller and more complex buildings. These developments have also resulted in an increase of potential risks associated with building fires. During the past several decades, the construction of tall buildings has been booming in Korea. However, the fire safety design for buildings has not been properly established to catch up to these demands, and fire losses are increasing. It is essential to understand that fire safety engineering cannot prosper alone, and it is not even enough to be supported by research in that specific area. Fundamental research requires support from other disciplines and from multidisciplinary research groups. Performance-based design is becoming more common as facilities incorporate unique features to achieve aesthetic, cost and functional goals while maintaining safety levels for building occupants and emergency responders. Performance-based design allows for significant design flexibility; however, therein lies a great responsibility to maintain fire protection features that might go beyond those required by code. Without knowledge of the mitigating features, a well-intentioned contractor or designer could compromise the building's safety during future renovations.","PeriodicalId":12289,"journal":{"name":"Fire Science and Technology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74649028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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