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This special issue of Fire Technology is devoted to scientific studies of facade fires, including experiments, computer models, design, technology, and regulations. The building facade is one of the most important aspects of an architectural design, taking up around 15%-25% of the total construction cost. The 4th paper, from I Southwest Jiaotong University i and I Sichuan Fire Research Institute i performed multiple full-scale facade fire tests on a 12-story building that was covered by the expanded polystyrene (EPS) foam and a plaster layer. [Extracted from the article]

Building information modelling (BIM) is widely considered to be leading the digital transformation of the AEC industry because of its data management capabilities among different stakeholders and across the building life-cycle. Fire safety engineering (FSE) is one of the disciplines that has been excluded for a long time from integrated approaches such as BIM, even though ensuring fire safety is a fundamental aspect of building performance. This paper presents a systematic literature review of BIM–FSE integration methodologies to highlight its potentialities for building life-cycle management and the digital transformation of the AEC domain. The findings show that the majority of BIM–FSE applications are focused on fire and evacuation simulations, followed by detection, monitoring and real-time emergency management. Technologies that are often involved in BIM-based fire safety solutions are CFD-based technologies, game- augmented and virtual reality, and the internet of things. Native formats are the most used for data sharing, while open standards still lack adequate data structures for FSE applications. The review highlights the benefits, embedded potentialities and limitations of the BIM–FSE integration in a decade of research studies. Future research directions for the digital transformation of FSE through BIM are proposed in a research agenda. [ABSTRACT FROM AUTHOR]

Sprinkler system can be very reliable and effective way to reduce fire risks in buildings if maintained properly. When the sprinkler system operates as designed, the temperatures affecting the load-bearing structures are often relatively low and the structural resistance is typically not compromised. Holistic Structural Fire Engineering (SFE) provides an opportunity to take active systems, like sprinklers, into account in the design. However, it is important to ensure that if the sprinkler system does not operate as designed, the consequences are still tolerable. Even though there are options to account sprinkler system in SFE, there is a lack of consistent guideline (at least in Finland). This can lead to totally different structural fire design and safety in similar buildings, depending on the interpretation and assumptions made. This paper presents a framework to take the effect of the sprinkler system consistently into account in SFE. The framework is based on Finland's fire regulations and on experience of multiple projects. Two case-examples, where this framework has been applied are presented in the paper. [ABSTRACT FROM AUTHOR]

In the past three decades, fire engineering has experienced fast development worldwide. Fire regulations for building industry were moved from prescriptive description to performance-based specification. This trend started in the UK in the 1980s and spread to other western countries. Hong Kong closely followed the UK development and adopted the approach of performance-based design (PBD) for the Hong Kong International Airport and MTR stations in the early 1990s. The Government of Hong Kong SAR formally recognised the PBD approach in the prescriptive codes of practice in the mid-1990s and developed the performance-based code (PBC) in the 2000s. This PBC was promulgated in 2011. The evolution in fire engineering impacted the fire community in Mainland China. The State Key Laboratory of Fire Science (SKLFS) was established in University of Science and Technology of China (USTC) in 1991. Then fire science and fire engineering stepped into the fast development track. The building industry in Mainland China started to adopt the PBD approach in the early 2000s for the significant developments including large airport terminals, railway and metro stations, super high-rise buildings, and mega commercial centres. However, a structured PBC system is not available within the regulatory framework to date. Adoption of PBD approach is slowing down in recent years. This paper presents a review of fire engineering development in Hong Kong and Mainland China. The review focuses on the development of the PBC in Hong Kong, and the PBD approach and fire research in Mainland China in the past 30 years. [ABSTRACT FROM AUTHOR]

Risk-based design and assessment methods are gaining popularity in performance-based structural fire engineering. These methods usually start by defining a set of hazard scenarios to use as analysis inputs. This approach, proven highly effective for other hazard types such as earthquakes, may not be optimal for fire safety design. Indeed, the strong coupling between the fire phenomenon and structural features enables an ad-hoc design variable selection (and/or optimisation) to reduce fire intensity, making fire scenarios additional design outputs. In addition, such a coupling effect implies that fire scenarios maximising consequences are structure specific. Building on these considerations, this paper discusses the limitations that arise at different analysis steps (i.e., fire-scenario and intensity treatment, identifying fire intensity measures, probabilistic fire hazard analysis, developing fire fragility models, and risk calculation) when using conventional risk-based approaches for design purposes. Furthermore, it compares such approaches with a fire safety design methodology (the Consequence-oriented Fire intensity Optimisation, CFO, approach) that addresses the identified limitations. The potential benefits of integrating the two approaches are also discussed. Finally, the fire design of a simplified steel-girder bridge is introduced as an illustrative example, comparing the consequence metrics and design updating strategies resulting from the two approaches. [ABSTRACT FROM AUTHOR]

Global fire performance of structures in fire is proven to be more advantageous in many cases of engineering practice than the prescriptive fire resistance based on isolated structural member testing. Hybrid fire simulation (HFS) is a novel well-suited method trending in recent years for analysis of global performance of structures in fire. In the principles of this method, the part of a structure which has unknown behavior or is uncertain to be numerically modeled (subjected to fire) would be physically tested, while the rest of the structure is numerically simulated. HFS method enables capturing the beneficial interaction mechanisms evolving between fire-exposed structural members and the adjacent cooler substructure. Due to the continuous temperature increase in a fire test and the existing thermal inertia as well as the rate- and temperature-dependent material behavior of structures exposed to fire, a real-time performance in hybrid fire simulation counts as a necessity. This challenge is more critical for hybrid fire simulations with higher applied heating rates relevant to structural fire engineering. Within scope of this paper, (a) a robust and rigorous approach for real-time HFS is presented; (b) a series of proof-of-concept studies of different hybrid fire simulations with various applied heating rates are carried out for a thermomechanical benchmark problem; (c) the important results of four representative hybrid fire simulations with relevant heating rates to structural fire engineering are discussed; (d) the importance of an appropriate calculation method for stiffness update of the fire-exposed structural member over HFS procedure is highlighted, and e) the precision and accuracy of the applied HFS approach with respect to interface error and real-time degree are evidenced. [ABSTRACT FROM AUTHOR]

In fire safety engineering, cost–benefit analysis provides a systematic method to assess whether the projected benefits from a fire safety measure outweigh its costs. However, there remains a wide discrepancy between methods used in the field for cost–benefit analysis, as well as a lack of quantitative data on the costs and economic impact of fire protection in buildings. In a recent research project, a reference methodology was proposed based on Present Net Value evaluation and on a combination of specialized construction database, fire statistics, and numerical modeling for estimation of the cost components. This paper presents the application of the methodology to four case studies. The case studies allow describing the methodology, the collection of data, fire statistics, and loss estimation, as well as illustrating how the methodology can support decision-making when multiple alternatives are compared. Under the assumptions adopted for the single-family house and the residential timber building case studies, it is found that for every 1$ invested in sprinklers, $1.06 is saved. This benefit–cost ratio increases with increasing valuation of indirect losses and statistical value of life. Sensitivity analyses are provided to explore the robustness of the investment recommendations. The results of evaluations, adapted from the presented case studies with project-specific inputs, can support decision making for policy makers, insurance companies, and individual building owners. [ABSTRACT FROM AUTHOR]

Fire statistics mirror the outcome of fire prevention. Most fire statistics in Germany deal with the loss of life, value, and fire department actions (number of interventions, nozzles used, or alarm category like a false alarm). However, these results also represent the safety level the legislator has set through the prescriptive building regulations. The current statistics cannot evaluate the level of fire safety and the fulfillment or necessity of fire safety precautions. Today, expert judgment from firefighters is necessary to fill this gap. Here, we show the first evaluation of fire prevention and hazard protection measures by evaluating 900 potentially harming fires throughout Germany. In contrast to minor fires, these fires have advanced to the extent that they could potentially violate the protection objectives outlined in building regulations. The fire department association developed a questionnaire to evaluate the fire safety level and possibly reduce unnecessary fire safety regulations. One hundred twenty-three fire departments carried out the questionnaire, which are responsible for 25% of the German population. Fire prevention officers of the fire departments went to the scene after the fire was extinguished, and the fire safety concept of the building could be evaluated. We found a high rate of injuries, smoke spread, need for rescue by firefighters, and higher than expected firefighter response times after arrival at the scene. Surprisingly, smoke spread rates correlated with building height and not with building age. It was even possible to assess the risk of multiple casualties. Overall, the questionnaire results give insight into the current level of fire safety in existing buildings. Ways and rates for smoke and fire spread prove the importance of second escape routes and the influence of human misconduct. According to these results, current building code regulations are sufficient to prevent fire spread. On the other hand, smoke spreading is a severe threat to people's safety. For example, the data shown can be applied in Bayes nets or other risk calculations to optimize individual building designs or even governmental building codes concerning fire safety engineering. Based on our observations, science, and building codes, authorities could in the future establish a performance-based building code instead of the current prescriptive code. This paper presents the first approach in Germany to quantify the expert judgment of fire departments and use it as a source of knowledge for fire prevention. [ABSTRACT FROM AUTHOR]

U-shaped structures are very common in the facade of buildings, which have a significant impact on fire spread. In this paper, the effect of the geometrical factor (α), the cross-sectional area (A), the height (H) on the upward fire spread in u-shaped structures are analyzed based on the fire spread rate (Vf) and the pressure difference between the top and the bottom (ΔP) through full-scale experiments and simulations. A dimensionless structure parameter α H / A is put forward to analyze the coupling effect of the structure size. It is found that Vf increases in the form of logarithmic function as α increases. ΔPmax increases in the form of exponential function as α increases; both Vf and ΔPmax decrease in the form of exponential function as A increases; Vf is positively correlated with H linearly. ΔPmax increases in the form of quadratic function as H increases; both Vf and ΔPmax increase in the form of Slogistic function as α H / A increases. When α H / A ≤ 17.2 or α H / A ≥ 38.8, α H / A has little effect on ΔPmax. The Vf in the non-overhead structure is very close to that in the overhead structure. This study can provide a theoretical guide for the fire protection design of u-shaped structures covered with insulation materials in practical engineering. [ABSTRACT FROM AUTHOR]

Estimation of design fires and thermal exposure conditions is an important step in structural fire engineering procedures. Mass timber, as a combustible material, may contribute to the fire intensity, yet there lacks methods to estimate design fires in compartments with exposed timber. This paper summarizes available experimental data on the contribution of exposed timber to heat release rate, describes a simple analytical method to evaluate this contribution, and discusses the effects on time–temperature curves and required firefighting resources based on a case study. Results show that the total heat release rate in compartments increases with the surface of exposed timber. This total heat release rate can be conservatively estimated using empirical relationships for ventilation-controlled burning rate and charring depth. In estimating gas temperature–time curves, both external flaming and extended fire duration combustion models can be applied to obtain an envelope of fire severity inside the compartment and for external spread. The proposed assessment approach provides a method to evaluate realistic design fires in timber buildings and to estimate the water supply required to put out these fires. Accurate modeling of the contribution of timber to fire severity is important for the design of mass timber construction as well as for the safety of firefighters. [ABSTRACT FROM AUTHOR]

Engineered timber is increasingly in demand for tall buildings due to its positive impact on building sustainability. However, quick adoption raises fire engineering questions regarding flammability and structural performance. Understanding the behaviour of timber in fire is crucial, particularly for structural calculations of tall buildings. The charring rate of timber plays a significant role in its structural performance because the loss of cross section reduces the load bearing capacity of the element. Eurocode-5 (EC5) provides a simple method to calculate the charring rate and it is widely adopted for design in many countries while more complex physics-based models exist but are rarely used for design. For example, we want to know when EC5 underpredicts or overpredicts and by how much. This paper compares different data-driven methods, including statistical and artificial intelligence algorithms, for predicting the average charring rate of timber in fire. A new database of charring rates, VAQT, was created comprised of 231 furnace tests of timber products found in the scientific and technical literature. Statistical methods such as ridge regression (λ = 0.001) predict the charring rate with a minimum 11% error whilst EC5 predicts with 27% error. A trained neural network predicts the charring rate with minimum 9% error. This paper presents a novel database of timber charring experiments and provides a set of data-driven predictive models, all of which calculate the average charring rate with a significantly higher accuracy than EC5 for a wide range of mass timber products. [ABSTRACT FROM AUTHOR]

Probabilistic analysis is receiving increased attention from fire engineers, assessment bodies and researchers. It is however often unclear which probabilistic models are appropriate for the analysis. For example, in probabilistic structural fire engineering, the models used to describe the permanent and live loads differ widely between studies. Through a literature review, it is observed that these diverging load models are based on surveys conducted between 1893 and 1976 and that widely adopted assumptions, such as the rule for combining permanent and live loads into the total load effect, are commonly adopted based on precedent. The diverging current models however relate to mostly the same underlying datasets and basic methodologies. Differences can be attributed (largely) to specific assumptions in different background papers, which have become consolidated through repeated use in research papers and adoption in background documents to codes. By reviewing the studies underlying currently applied probabilistic load models in structural fire engineering, a consolidated probabilistic load model is proposed in this paper. It is concluded that the total load effect is ideally described by KE·(G + Q), with KE the model uncertainty for the load effect, G the permanent load, and Q the imposed load. The model uncertainty KE can be described by a lognormal distribution with mean equal to unity and coefficient of variation (COV) of 0.10. The permanent load is preferably modelled by a normal distribution with mean equal to the nominal permanent load, and a COV which can either be assessed on a project specific basis, or can be set to 0.10 for a first assessment. For common occupancies (office, residential), the live load is preferably modelled by a Gamma distribution. The mean live load can be taken as 0.2 times the nominal, and the live load COV can be taken as 0.60 for large load areas (> 200 m2) and 0.95 for smaller load areas (< 100 m2). Comparison between the failure probabilities of steel and concrete columns subject to fire, considering the proposed consolidated model and two currently commonly used models, indicates that relative differences of the probability of failure can be in the order of 10%. Live load models for evacuation routes and warehouses require specific study and are outside the scope of the review. [ABSTRACT FROM AUTHOR]

Coal fires are global disasters, and China suffers the most serious coal fire disasters in the world. This paper introduces detailed detection and extinguishing methods for the wide range and complex coal fires at the No. 1 well in the Fukang mining area. First, the characteristics of the large and complex coal fire areas in the No. 1 well in the Fukang mining area are introduced, and 5 large fire areas are detected using the comprehensive detection range method, which detects fire areas before fire engineering practices are implemented. From the characteristics of this large-scale, complex coal fire, the zonal fire extinguishing scheme is formulated, designed, and applied, and the "shallow open fire stripping—construction of the boundary isolation zone—drilling and grouting in the deep fire area" series of events is utilized in the zonal fire extinguishing scheme. A new type of sodium silicate gel in compressive moisturizing plastic packing materials is used, an automatic grouting system is developed, and effective grouting processes are proposed, which can be adjusted according to the grouting effect analysis of the grouting parameters to determine the natural sedimentation and diffusion radius. After the construction was completed, the fire extinguishing effect was tested, revealing that the temperature in the fire zone cooled in a short time, and no subsequent heating phenomenon occurs. The method proposed in this paper provides guidance and a reference for other coal fires in the world. [ABSTRACT FROM AUTHOR]

In Germany, building codes relating to fire safety are mainly prescriptive nature. Therefore, fire safety engineering is based on a combination of expert judgment and reverse engineering of prescriptive rules. This necessitates to connect the given objectives with the detailed prescriptive rules—if not already described within the law or bylaw. This paper proposes a table relating the fire safety objectives of European building regulations and their German counterpart with the prescriptive model building code in Germany. In addition, a risk curve for prenormative work is also given. This represents the prescriptive regulations concerning in terms of fatalities of a level acceptable to society and emphasizes the lower degree of acceptance of multiple fatalities occurring in a single incident. This residual risk limit represents the opinion of German firefighting associations. Data taken from the London area supports the suggested slope rate, as the level of safety in Britain is similar to that in Germany. The table of prescriptive building regulations and their corresponding objectives aids everyday planning decisions in the context of determining adequate compensation without missing out any essential aspects, such as firefighting and firefighter safety. The proposed table forms the basis of the current discussion of a European model performance-based model building code (PBC) within the European Committee for Standardization CEN. Moreover, the risk curve is the first to be discussed in Germany that takes into consideration the societal aspect. It forms an appropriate basis for performing fire safety risk calculations based on fault tree analysis or Bayes nets. The CEN working group for fire safety engineering discusses both aspects of the current development of a European, performance-based fire safety code. It is presented here for the first time. [ABSTRACT FROM AUTHOR]

The traditional design fires commonly considered in structural fire engineering, like the standard fire and Eurocode parametric fires, were developed several decades ago based on experimental compartments smaller than 100 m2 in floor area. These experiments led to the inherent assumption of flashover in design fires and that the temperatures and burning conditions are uniform in the whole of the compartment, regardless of its size. However, modern office buildings often have much larger open-plan floor areas (e.g. the Shard in London has a floor area of 1600 m2) where non-uniform fire conditions are likely to occur. This paper presents observations from a large-scale fire experiment x-ONE conducted inside a concrete farm building in Poland. The objective of x-ONE was to capture experimentally a natural fire inside a large and open plan compartment. With an open-plan floor area of 380 m2, x-ONE is the largest compartment fire experiment carried out to date. The fire was ignited at one end of the compartment and allowed to spread across a continuous wood crib (fuel load ~ 370 MJ/m2). A travelling fire with clear leading and trailing edges was observed spreading along 29 m of the compartment length. The flame spread rate was not constant but accelerated with time from 3 mm/s to 167 mm/s resulting in a gradually changing fire size. The fire travelled across the compartment and burned out at the far end 25 min after ignition. Flashover was not observed. The thermocouples and cameras installed along the fire path show clear near-field and far-field regions, indicating highly non-uniform spatial temperatures and burning within the compartment. The fire dynamics observed during this experiment are completely different to the fire dynamics reported in small scale compartments in previous literature and to the assumptions made in traditional design fires for structural design. This highlights the need for further research and experiments in large compartments to understand the fire dynamics and continue improving the safe design of modern buildings. [ABSTRACT FROM AUTHOR]

Reported in this paper is an exercise that contributes to the fire load database for fire severity analysis. The movable fuel load data was collected by the weight-inventory method from a specific building type, namely school buildings located within the metropolitan area of Sydney, Australia. The data was analysed to obtain statistical descriptions of fire load density in terms of probability density distributions. The results were compared with the similar data obtained from other countries. It was found that while basic statistical characteristics show similarities globally, some other characteristics, particularly the 90th percentile, may differ from one country to the other. This outcome suggests that fire load selection for design fires in fire safety engineering design and assessment should be better based on local data and a careful review of the unified approach in the international fire engineering guidelines is warranted. [ABSTRACT FROM AUTHOR]

This paper presents modifications to the adoption of a Performance-Based Earthquake Engineering (PBEE) framework in Probabilistic Structural Fire Engineering. Potential Fire Severity Measures, which capture significant characteristics of fire scenarios, are investigated. A suitable Fire Severity Measure (FSM), which best relates fire hazard intensity with structural response, is identified by satisfying efficiency and sufficiency criteria as described by the PBEE framework. The study also implements a new analysis method called Fire Stripe Analysis (FSA) to obtain the relationship between FSM and the structural response. In order to obtain the annual rate of exceedance of damage and repair cost/time for an office building, an occurrence model and an attenuation model for office structure fires are generated for both Christchurch city and New Zealand. The process is demonstrated with the help of a case study performed for a steel–concrete composite beam. Structural response is recorded for the beam exposed to several fire profiles which are generated by varying fuel loads from 200 MJ/m2 to 1000 MJ/m2 and ventilation factors from 0.02 m1/2 to 0.08 m1/2. FSA and dispersion curves of structural response are plotted for every fire severity measure. Cumulative incident radiation is found to be the most efficient and sufficient FSM. The mean annual rate of exceedance of given levels of fire severity and structural response are evaluated for both New Zealand and Christchurch city. It is found that Christchurch city has a 15% less probability of exceedance of the given fire severity level in comparison to the whole of New Zealand. The extension of this work would facilitate designers/insurers to evaluate the probability of damage or failure of a structure due to a probable fire hazard. [ABSTRACT FROM AUTHOR]

Probabilistic techniques deal with the randomness of variables and reliability of safety system but their application in fire safety engineering is limited due to the lack of data related to real structures subjected to real fires. This can be overcome by analysis of national fire statistics provided by fire departments. Fire statistics databases are a collection of data from real structures subjected to real fires and provides an understanding of real effectiveness of different fire safety measures (i.e. compartmentation) which influence the spread and growth of fire, and ultimately their monetary consequence. The ability to understand the realistic responses of buildings in fire is the fundamental basis of British Standards PD 7974-7, which provides data to perform probabilistic risk assessments for fire. However, the current data presented by BS PD 7974-7:2003 (referred to as PD 7974-7 within this paper) was developed between 1966 and 1987. This research has used the USA fire statistic database of 2014 to recreate the tables present in the PD 7974-7, compare the results, and understand their evolution in time. The comparison between PD 7974-7 and the USA fire statistics introduced in this paper shows that modern fire frequency can be up to more than 10 times smaller than presented in PD 7974-7; area damage in m2 and spread of fire are linked to automatic extinguish systems effectiveness and greater in the USA fire statistics than predicted by PD 7974-7. This clearly demonstrate the need of updates to PD 7974-7 and feeds towards a better understanding of the robustness, and potentially the resilience, of real structures in fire. [ABSTRACT FROM AUTHOR]

Additionally, Naser [[2]] presented a state-of-the-art review on AI-based methods and their applications in the fire engineering domain. For tunnel fires, Wu et al. [[5]] created an extensive database from numerical simulations on these fires and then used AI methods to explore such a database. With the rise of transformative technologies: such as artificial intelligence (AI), Internet-of-Things (IoT), robotics, sensors etc., the field of fire engineering and safety is embracing a new era to realize smart and fire-resilient structures and systems. [Extracted from the article]

The main objective of this paper is to evaluate the validity of the existing methods for analytically solving the governing equation of smoke filling in enclosures with floor leaks and growing fires. Since the complete form of the governing equation is inseparable, it can hardly be exactly solved analytically. Up to now, there are mainly five analytical solutions available in the literature. The first is derived by Mowrer (Fire Saf J 33: 93–114, 1999), the second is derived by Yamana and Tanaka (Fire Sci Technol 5: 31–40, 1985; Fire Sci Technol 5: 41–45, 1985), and the other three are derived by Delichatsios (Fire Saf J 38: 97–101, 2003; Fire Saf 39: 643–662, 2004). Among these solutions, the first has been incorporated into the SFPE handbook (SFPE handbook of fire protection engineering, 5th edn. Springer, New York, 2016), and one of the Delichatsios' solutions has been incorporated into the ISO standard (Fire safety engineering—Requirements governing algebraic equations—Smoke layers, 2006). These analytical solutions provide convenient ways for estimating the smoke-interface height. However, it should be noted that all of these solutions are approximate for the case of "floor leak & growing fire", so they must be used with caution. By comparing with the "exact" numerical solutions of the governing equation, errors of the five analytical solutions are calculated systematically. An absolute error contour plot and a relative error contour plot are made for each solution, which can be directly used to judge the validity of the solution. It is found that all the five analytical solutions sometimes produce considerable errors, and the error distribution characteristics are quite different from one solution to another. The error sources are analyzed. The analyses provide not only explanation for the error distribution characteristics but also deep insights into the analytical solutions. Based on the error contour plots made for each solution, the prediction of the corresponding solution can be corrected to a more accurate value. An example is presented to illustrate how to do this. [ABSTRACT FROM AUTHOR]

References 1 Blais MS, Carpenter K, Fernandez K. Comparative room burn study of furnished rooms from the United Kingdom, France and the United States. Dear editor, We have concerns about the Blais et al. paper "Comparative Room Burn Study of Furnished Rooms from the United Kingdom, France and the United States" in the March 2020 issue of I Fire Technology i [[1]]. The study compared fire growth and smoke toxicity in mock burn rooms each containing a couch and chair purchased from either the United Kingdom, France, or the United States. [Extracted from the article]

A fire risk assessment has always been a challenging task. Performance-based approaches to fire engineering have shown that risk-based decisions and fire scenarios are fundamental elements that must be considered in fire safety strategies. A correct assessment of the fire risk allows all the involved stakeholders to identify a specific strategy from among a variety of possibilities. A risk assessment is the best tool to identify comparable fire protection strategies and to measure the reduction in fire risk that can be obtained with each specific prevention and protection measure, i.e., by means of different fire safety strategies. The present paper illustrates a method that takes into account several well-known methods, even some that were developed as far back as in the early seventies. The method is named "FLAME" (Fire Risk Assessment Method for Enterprises). FLAME considers fundamental fire safety aspects instead of making use of sophisticated and time-consuming methods like CFD. FLAME uses the "Fire Safety Concept Tree", which is explained in detail in the NFPA 550 Standard, as a reference scheme. The method allows the risk to the occupants to be evaluated separately from the risk to the building. Over the years, we have tested the method considering different kinds of buildings and occupancies. We here report the results of an application of the FLAME method to hospitals and health-care facilities. Overall, about 300 compartments (overall size of about 60,000 m2) were analysed, including two hospitals of about 200,000 m2 each. The results of the risk estimation with the FLAME code have been found to be coherent with Italian fire code prescriptions. About 44% of the compartments were defined as being at a Medium risk and 39% as being at a high risk (according to the Italian Fire Code). More than 60% of the hospital compartments were defined as being at a High risk. A good agreement was obtained between the RSET results with those of the method proposed in FLAME when using the current performance-based regulation criteria. The RSET estimation in FLAME considers the occupants' behaviour and the actual characteristics of the occupants in clinics or hospitals, who often have difficulties due to reduced mobility or an incapacity to understand emergency instructions. [ABSTRACT FROM AUTHOR]

Widely used in earthquake engineering, Hybrid testing is promoted in various domains such as wind engineering, coastal structures and fluid-structure interaction. It also begins to be applied to fire engineering (Hybrid Fire Testing or HFT) for coupling fire tests and numerical simulations. However, HFT is still in its infancy. Yet, some tests have been performed and some algorithms have been developed. Recently, Mergny et al. [1] proposed a framework based on linear control system theory for a displacement control procedure. It uses proportional integral (PI) controller and allows performing HFT with non-linear substructures. The method was validated numerically but no analysis was provided about stability. This paper aims to describe the effects on stability of the main sources of errors in the case of HFT using PI control, namely delays, experimental errors and estimation of the stiffness of the physical substructure that is essential for most of the methodologies that have been developed so far. The research shows first through the equations of a single degree of freedom (SDOF) system that the estimation of the stiffness is a potential source of instability and affects directly the design of the PI controller. A simplified model for MDOF system was developed. Then, the research highlights that the effect of the experimental errors can involve a modification of the apparent mechanical response of the specimen and causes instability. However, this effect can be greatly limited. Finally, the delay is not a source of instability. A virtual hybrid test is performed in a steel frame and shows that the simplified model is a satisfying approximation and that described effects of the estimation of the stiffness established for a SDOF system can be observed for a complex system. [ABSTRACT FROM AUTHOR]

The 2016 DiNenno Prize recognizes oxygen consumption calorimetry as a significant technical achievement that has had a major impact on public safety. Oxygen consumption calorimetry has made the measurement of heat release rate of a fire a routine part of fire testing for both research and for regulatory compliance. Heat release rate is a primary metric of fire size which is foundational in modern fire protection engineering. The 2016 Philip J. DiNenno Prize is awarded to Dr. William Parker, with ample commendation to his deceased collaborator, Dr. Clayton Huggett. Others who made contributions to the early development and application of oxygen consumption calorimetry include Peter Hinkley, William Christian, Thomas Waterman, Darryl Sensenig, Ralph Krause, Richard Gann, Vyto Babrauskas, Gunnar Heskestad, Norm Alvares, Donald Beason, and Brady Williamson. This review presents an overview of the background to the technological development and its impact on public safety. [ABSTRACT FROM AUTHOR]

Fire development inside a train car is a topic that has not been studied extensively due to the complexity of the problem and the need for a real train car and the appropriate facilities to conduct these tests in a controlled environment. This paper presents detailed experimental data on fire development inside a real intercity train car. The facility used for the tests is capable of conducting such large-scale fires and measuring the heat release rate using oxygen consumption calorimetry. Thermocouples and plate thermometers were installed inside the train car to provide an insight of the fire development. A number of cameras were also placed inside the car and in the tunnel providing live videos during the test. The peak heat release rate was 32 MW at 1081 s after ignition, and the fire burned 83% of the initial fire load. Flame spread data and recordings of window breaking events are discussed and compared to the heat release rate data. A local flashover-type phenomenon where the fire involved all combustibles at the rear of the car was found to occur. [ABSTRACT FROM AUTHOR]

The knowledge in the field of structural fire engineering has been greatly advanced through assessment of a number of real fires (WTC, Torre Windsor, Broadgate, etc.) and, especially, by the Cardington series of full scale structural fire tests. This knowledge has been used to validate and verify the use of computational finite element models that have expanded the range of structures that can be investigated under severe fire exposure. This paper presents a selection of key lessons learned by the authors through the assessment of structures in fire for real commercial building projects. The key areas of sensitivity that have been encountered are described and a discussion of each point presented. The paper is aimed at describing potential weaknesses that have been observed in the commercial work of the authors, often driven by the requirements for efficient ambient structural design. The paper concludes with some suggested advice for structural engineers aimed at increasing the general robustness of building structures. This is based on designing out as far as possible in the ambient design of a structure the potential weaknesses identified in past project work. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses articles in the issue on topics including risk acceptance concepts applied in probabilistic fire safety engineering; frameworks for probabilistic structural fire safety evaluations; and the identification of suitable fire severity measures.

Over the last decade, the electric vehicle (EV) has significantly changed the car industry globally, driven by the fast development of Li-ion battery technology. However, the fire risk and hazard associated with this type of high-energy battery has become a major safety concern for EVs. This review focuses on the latest fire-safety issues of EVs related to thermal runaway and fire in Li-ion batteries. Thermal runaway or fire can occur as a result of extreme abuse conditions that may be the result of the faulty operation or traffic accidents. Failure of the battery may then be accompanied by the release of toxic gas, fire, jet flames, and explosion. This paper is devoted to reviewing the battery fire in battery EVs, hybrid EVs, and electric buses to provide a qualitative understanding of the fire risk and hazards associated with battery powered EVs. In addition, important battery fire characteristics involved in various EV fire scenarios, obtained through testing, are analysed. The tested peak heat release rate (PHHR in MW) varies with the energy capacity of LIBs ( E B in Wh) crossing different scales as P H R R = 2 E B 0.6 . For the full-scale EV fire test, limited data have revealed that the heat release and hazard of an EV fire are comparable to that of a fossil-fuelled vehicle fire. Once the onboard battery involved in fire, there is a greater difficulty in suppressing EV fires, because the burning battery pack inside is inaccessible to externally applied suppressant and can re-ignite without sufficient cooling. As a result, an excessive amount of suppression agent is needed to cool the battery, extinguish the fire, and prevent reignition. By addressing these concerns, this review aims to aid researchers and industries working with batteries, EVs and fire safety engineering, to encourage active research collaborations, and attract future research and development on improving the overall safety of future EVs. Only then will society achieve the same comfort level for EVs as they have for conventional vehicles. [ABSTRACT FROM AUTHOR]

Pedestrian evacuation models are often used to assess life safety in the performance-based design process within fire safety engineering. Within this paper, a summary of data collected via an international online survey regarding the models and users' experiences and needs is presented. This survey consisted of 22 questions focusing on: the assessment of the pedestrian evacuation model user community; their stated importance of model features to select a model; usage/awareness of models; knowledge of model validation and verification; training; and usage of multiple models. As such, the survey allowed the collection of information useful for instructing future pedestrian evacuation model development. The survey represents an expanded version of a previous survey conducted by the authors in 2011. Results with the previous survey were compared to identify any changes in preference and usage by pedestrian evacuation model users. The survey was completed by 234 respondents from 41 countries. The respondents had a wide range of education and occupational backgrounds and use models for a variety of different purposes. The results identified a total of 72 pedestrian evacuation models currently in use and indicated the most known models. In addition, the most used models were identified, and the results highlighted that the three key factors used to select a pedestrian evacuation model are overall consistent with the results of the 2011 survey: verification and validation, documentation, and data output of the model. [ABSTRACT FROM AUTHOR]

Familiarity is widely accepted as a key variable for the exit route selection of occupants of a building in emergency egress, but how to evaluate it has not been well researched. In addition, familiarity with general space layout (building familiarity) and familiarity with exits (exit familiarity) are often interchangeably used, which may cause inappropriate understanding of building and occupant characteristics among fire engineers and architects. In the current study, a paper-based survey was conducted to examine the difference between the two familiarities in a six-story library building. The two familiarities were implicitly evaluated by the spatial knowledge of the participants on the locations of restrooms, elevators, stairways for exit purposes in an emergency, and their current location. Sixty-nine valid responses of the participants' spatial knowledge were semi-quantitatively evaluated based upon the accuracy of the answered position against the actual position. The results reveal that the two familiarities are not synonymous and needs to be understood and handled differently in fire engineering. In particular, the location of emergency-only exit stairways was perceived as low as 20% of non-emergency-only stairways; on average, each of the former and latter stairways was perceived by 8 and 33 participants out of 69 participants, respectively. This result raises concerns about the efficacy of the emergency-only-exit concept. The direction of the next destination out of a building was found to be a key factor to determine the travel route within a building where occupants have good familiarity with the building and surrounding places. [ABSTRACT FROM AUTHOR]

Along with the rapid urbanization and economic growth in China over the last four decades, the higher education in Fire Safety Science and Engineering has been developed and changed significantly. This work systemically reviews the origin and evolution of fire safety higher education history in China, from Fire Protection Technology (before the 1980s) to Fire Safety Science and Engineering (from about 1985 to the 2010s) and to Human-Oriented Public Safety and Smart Firefighting (from the 2010s to today). The scopes of fire safety discipline are discussed by introducing the requirements of firefighters, registered professional fire protection engineers and safety engineers in China. The courses and curriculum in fire safety higher education in representative universities are introduced and compared in detail. By comparing their undergraduate and postgraduate programmes, we explain the context of fire safety education in different universities. From a historical viewpoint, we introduce the unique features and the diversity developed in different institutes, based on the evolution of programme documents and first-hand teaching materials. This review aims to introduce the higher education systems of fire safety in China to the world and encourage more international collaboration with the Chinese fire safety science and engineering communities in the future. [ABSTRACT FROM AUTHOR]

Following the attacks on the World Trade Center in New York City on September 11, 2001, several large studies were undertaken to look at the evacuation. The studies began from 18 months to 4 years after the event, and although there were similarities in the data sets collected in these studies, each set out to answer or contribute to a somewhat different purpose-investigation into the collapse of the towers, emergency preparedness in the workplace, and enhancements in the computer simulation of the evacuation of high-rise buildings. The studies used a variety of data collection techniques. This paper briefly describes the studies, their study populations, summary findings and long-term impacts. [ABSTRACT FROM AUTHOR]

Structural fire safety is one of the key considerations in the design and maintenance of the built infrastructure, yet there are serious limitations in the current approaches to structural fire safety and also severe knowledge gaps in the literature. Two main reasons for these limitations are the lack of significant research activities in this field and lack of educational and training programs in the universities. This paper reviews the current state-of-the-art and identifies the research and training needs for improved fire safety in the U.S. These discussions are based on a two-day workshop organized at Michigan State University which brought together many academics from U.S universities, international experts, and design professionals in the structural fire safety field. This paper summarizes the conclusions of the workshop and identifies the top ten research and training needs in structural fire safety. [ABSTRACT FROM AUTHOR]

This paper promotes a discussion about evacuation models and their relation with evacuation processes. For this reason, the question “quo vadimus” (i.e., from Latin: where are we going to?) intends to initiate this discussion. Therefore, a brief overview of the importance of the evacuation modelling analysis within the Fire Safety Engineering (FSE) context is presented. This paper also presents an analysis of the evacuation modelling process and some remarks on how the evacuation models' reviews are being done as well. Furthermore, along with the previous question, some other subsequent key-questions can be aroused and this paper intends to analyse them, namely: Do we need the evacuation models for understanding evacuation processes? Are we doing the evacuation models' reviews properly? Do we understand well the evacuation models? Do we understand the evacuation modelling process? [ABSTRACT FROM AUTHOR]

This paper presents the main results of six large scale fixed fire fighting system tests that were carried out in the Runehamar tunnel in September 2013. It describes the background and the performance of the system. The main fire load consisted of 420 standardized wood pallets and a target consisting of a pile of 21 wood pallets placed 5 m from the rear end of the main fire load. The purpose was to investigate possible fire spread. The water spray system is a deluge zone system delivering 10 mm/min in the activated zone. The detection system was simulated with use of thermocouple in the tunnel ceiling. The alarm was registered when the ceiling gas temperature was 141°C. After alarm was obtained the system was activated manually after a given delay time that was varied in the tests. The heat release rates in tests with fire suppression were reduced to 20-45 MW compared to 100 MW estimated for a free-burn test or 75 MW in test 6 with a failure of activation. Fire spread to the target was prevented after fire suppression. [ABSTRACT FROM AUTHOR]

Nuisance alarms have been identified as a leading cause of disabled smoke alarms in homes. In the 2013 Edition of NFPA 72, National Fire Alarm and Signaling Code, the Technical Committee approved requiring household alarms and detectors installed between 6 ft (1.8 m) and 20 ft (6.1 m) of cooking appliances to be listed for resistance to common cooking sources 2016 and for all household alarms, and detectors to be listed for resistance to common nuisances by 2019, respectively. There is currently no clear understanding of how 'resistance to common nuisance sources' should be defined within these requirements. In this paper, Statistical data, surveys, and alarm installations were assessed to quantify the potential impacts of reducing nuisance alarms toward overall public safety and reduction of fire loss. Based on these reports, it has been estimated that elimination of nuisance alarms may reduce annual U.S. fire deaths by as much as 10%, or 214 deaths per year (1050 injuries). This number does not account for negative potential consequences on death and injury rates, such as increased alarm costs or decreased sensitivity to real fires. A review of laboratory test data and studies evaluating household installation performance was conducted to identify and characterize common household nuisance sources, such as cooking (60% to 80% of nuisance alarms), water mist (1% to 40%), or increased sensitivity from long term contamination (up to 70% of nuisance alarms). Detailed recommendations are made based on existing data to address remaining information gaps and develop new performance test protocols in ANSI/UL 217 and ANSI/UL 268 product standards in order to meet the NFPA 72-2013 requirements. [ABSTRACT FROM AUTHOR]

Tunnels are key elements in modern traffic networks. Large-scale accidents and malicious threats, such as fires or explosions creating a blast loading, potentially carry very high economical and societal consequences. Compared to other statistically certain events, explosive-induced blasts in tunnels have an extremely low probability of occurrence but at the same time an enormous damage potential for structure, life, and environment. The paper presents a procedure for evaluation consequences of blast loading threat scenarios, focusing on the local and global structural integrity of tunnel constructions. Methods to capture the dynamic loading and the structural resistance, especially considering the dynamic soil response under large stresses and strains, are described. For that, a combined experimental and numerical approach is chosen, including characterization of the soil by dynamic triaxial experiments realizing stress levels of about 1 MPa, acting in 1 ms on the specimen. The analysis showed that the measured triaxial strength of the soil differed from the static by a factor of 2 for the friction angle. Furthermore, scaled experiments have been designed and conducted to demonstrate and investigate the behavior of a buried tunnel segment under blast loading. The results showed that realistic loading charges can cause massive cracking of the tunnel system and a soil sinking of up to 1 cm. Both experimental results obtained from the triaxial tests on the one hand and from the scaled tunnel experiments on the other hand have been validated using numerical models. The good agreement obtained is the essential input parameter for the evaluation of criticality in tunnels under blast loading scenarios. [ABSTRACT FROM AUTHOR]

Modeling the behavior of crown fires is challenging due to the complex set of coupled processes that drive the characteristics of a spreading wildfire and the large range of spatial and temporal scales over which these processes occur. Detailed physics-based modeling approaches such as FIRETEC and the Wildland Urban Interface Fire Dynamics Simulator (WFDS) simulate fire behavior using computational fluid dynamics based methods to numerically solve the three-dimensional, time dependent, model equations that govern, to some approximation, the component physical processes and their interactions that drive fire behavior. Both of these models have had limited evaluation and have not been assessed for predicting crown fire behavior. In this paper, we utilized a published set of field-scale measured crown fire rate of spread (ROS) data to provide a coarse assessment of crown fire ROS predictions from previously published studies that have utilized WFDS or FIRETEC. Overall, 86% of all simulated ROS values using WFDS or FIRETEC fell within the 95% prediction interval of the empirical data, which was above the goal of 75% for dynamic ecological modeling. However, scarcity of available empirical data is a bottleneck for further assessment of model performance. [ABSTRACT FROM AUTHOR]

Advanced simulation methods are needed to predict the complex behavior of structures exposed to realistic fires. Fire dynamics simulator (FDS) is a computational fluid dynamics code, developed by NIST for fire related simulations. In recent years, there has been an increase in use of FDS for performance-based analysis in the area of structural fire research. This paper discusses the FDS-finite element method (FEM) simulation methodology for structural fire analysis. The general methodology is described and a validation study is presented. A data element used to transfer data from FDS to FEM codes, the adiabatic surface temperature, is discussed. A tool named fire-thermomechanical interface is applied to transfer data from FDS to ANSYS. A high temperature stress-strain model for structural steel developed by NIST is included in the FEM analysis. Compared to experimental results, the FDS-FEM method predicted both the thermal and structural responses of a steel column in a localized fire test. The column buckling time was predicted with a maximum error of 7.8%. Based on these results, this methodology has potential to be used in performance-based analysis. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editors discuss various reports within the issue on topics including validation of fire models, importance of initial and boundary conditions in fire models, and fire experiments and simulations in compartment ventilation.

This paper aims to describe an alternative fire growth model that allows prediction of fire development, including time to flashover. The unpredictable nature of real fire development is incorporated into the model through use of probability distributions which can be defined using appropriate fire test data, when available. By assuming that the fire goes through five different stages starting from ignition and progressing to flashover, the total time to flashover may also be estimated. The model considers potential variability in the times at which the fire will undergo transitions between the various stages of development, using a state transition method called the semi-Markov process model. Different fire data may be incorporated into the model by defining appropriate statistical distributions for the transition descriptors, making the model flexible enough for use in a variety of applications important to both product design engineers and fire safety regulators. [ABSTRACT FROM AUTHOR]

The National Institute of Standards and Technology (NIST) conducted an extensive investigation of the collapse of the three tall World Trade Center (WTC) buildings. A central part of this investigation was the reconstruction and understanding of the initiation and spread of the fires. This paper describes the reconstruction of the fires, the thermal environment they created within the buildings, and the raising of the temperatures of the structural components. NIST analyzed thousands of documents, interviews, photographs, and videos to obtain information on the layout of the floors and the progress of the fires. Experiments provided information on the factors likely to have determined the fire growth. Simulations using the Fire Dynamics Simulator gave good agreement with the fire spread as observed at the windows. Imposition of the probable thermal environment on the structural steel produced maps of the probable temperature profile of the steel as the fires progressed. For WTC 1 and WTC 2, even in the vicinity of the fires, it was unlikely that the columns and floor trusses with intact insulation heated to temperatures where significant loss of strength occurred. This was in part due to the short time between aircraft impact and building collapse. There were regions of the towers in which the loss of structural strength of floors and columns, whose insulation had been damaged by aircraft impact, was likely. For WTC 7, even though the insulation was intact, the long periods of heating resulted in floor components whose temperatures exceeded 600°C, but columns did not exceed 300°C. [ABSTRACT FROM AUTHOR]

Over the years, much information has been gathered about fires in fire investigation reports and statistics. This information may have been collected nationally by an agency or an insurance company, or locally by the local rescue service. The information thus gathered can be used to learn from these fires and thereby lead to improved fire safety in buildings. This paper describes a method for discovering technical deficiencies in the fire safety of buildings. The method offers a means of analysing several fires systematically with the aim of identifying factors characteristic of a problem in the system studied. In this paper, the method is illustrated through a study of severe fires in school buildings in Sweden. The aim is to discover the underlying factors that cause some fires to grow and become severe. The method is considered a useful tool for discovering the underlying factors to or causes of fires. [ABSTRACT FROM AUTHOR]

The movement of smoke in buildings and tunnels is governed by a number of driving forces, including fire-induced buoyancy and expansion, stack effect, wind effect and mechanical ventilation. To manage smoke movement in buildings and tunnels, these driving forces need to be considered individually and collectively so that appropriate strategies and systems can be implemented to achieve desired smoke control objectives. This paper provides an overview of the driving forces for smoke movement in buildings and tunnels and for the current methods used to manage smoke movement in structures. [ABSTRACT FROM AUTHOR]

The impact of Photovoltaic (PV) installations on the fire safety of buildings must be considered in all building projects where such energy systems are established. The holistic fire safety of the building largely depends on how the fire safety of the PV installation is considered by the different actors during the design and construction process. Research has therefore been undertaken to study how performance-based regulations in combination with the lack of national guidelines affect the overall fire safety considerations for PV installations in Norway. Four factors were found to govern to which extent PV installations are emphasised in the fire safety design phase: (1) whether the building was first of its kind as a pioneering building, (2) whether the building was built before or after the publication of the 2018 revision of the norm NEK 400, (3) The level of knowledge and experience of the fire safety consultant, which in turn affects the use of performance-based engineering tools and the level of detailing in the design and construction phases, and (4) The degree of integration in the building. The main goal of the study is to give an insight and a contribution to the development of in-depth knowledge on how fire safety design for PV installations on buildings is handled in Norway, which may also be relevant to other countries with similar performance-based regulations. [ABSTRACT FROM AUTHOR]

Probabilistic fire simulation has been gaining interest in performance-based design approach. Very few evaluations on modelling performance can lead to unnecessary simulations which limit the understanding of fire engineering practitioners to select suitable model for a specific fire phenomenon. This study presents comparison of models' capabilities to recreate kitchen fire experiment through probabilistic assessments when there are various possibilities of fire spread can occur within the compartment. Such situation must consider the possible heat release rate curve from previously burning kitchen item, as this will effect on the possibility that other item igniting, and so enhance the intensity of fire. Determination of accumulated heat release rate data is assessed through the use of B-RISK and simplified model. Simulation input employs design fire for single furniture that was characterized through combination of peak growth and exponential decay functions using statistical analysis of fire severity characteristics from collated experimental data. Probabilistic correlation discloses that both models are able to produce results within an acceptable range of fire practice (> 20%), but B-RISK has better representation of possible cumulative heat release rate region than simplified model when more than 58% similarity of fire spread predictions among multiple items is achieved over different boundary ranges. [ABSTRACT FROM AUTHOR]

Kinetic parameters for serial pyrolysis reactions were calibrated from thermogravimetric analysis (TGA) data using Bayesian inference via Markov Chain Monte Carlo (MCMC) simulations assuming a serial reaction mechanism. Calibrations were performed for high-impact polystyrene (HIPS), bisphenol-A polycarbonate (PC), and poly(vinyl chloride) (PVC) at heating rates of 3 K/min and 10 K/min. The resulting parameter inferences are probabilistic as opposed to the point estimates calibrated in previous studies and are visualized using posterior probability density functions (PDFs) generated by kernel density estimation (KDE). Correlations between the parameters are identified and discussed. In particular, it is clear that pre-exponential constants and activation energies for a given reaction have a strong positive correlation. It is hypothesized that the degree of overlap in the posterior PDFs might be a measure of model adequacy. Point-estimates of the kinetic parameters were made by finding the mode of the posterior PDFs. For HIPS, it was determined that a one-reaction pyrolysis model is most appropriate, and that the posterior modes for $$\log \left( A_1\right) $$ and $$E_1$$ are $$19.5\,\log (1/s)$$ and 292 kJ/mol, respectively, for the 3 K/min data. To evaluate the effect of kinetic parameter uncertainty on predictions of burning rate, samples from the posterior PDF were used to simulate gasification and cone calorimetry experiments using the fire dynamics simulator (FDS). In some cases, it was found that models with fewer parameters provided better predictions due to over-fitting associated with greater model complexity. Another important observation is that for the predictions of PVC cone calorimetry, the time to peak heat release rate can range from around 40 s to 180 s for a number of different kinetic parameter combinations that all fit the TGA data fairly well. It is argued that the proposed methodology is necessary for progress in modeling of condensed phase physics for fire problems as it supports both model validation and engineering predictions. [ABSTRACT FROM AUTHOR]

With the increasing development of underwater equipment, electrical fire has become the focus of safety concern. To effectively guide the fire engineering design and incident management, this research proposes a priority assessment method for the electrical fire risks in typical Chinese underwater equipment cabins, which integrates the fault tree, modified analytic hierarchy process (MAHP), B-RISK fire zone model and Borda number ranking. Firstly, the method uses the fault tree to identify the fire sources (origins) and MAHP involving the numbers of accidents and regulations and the failure rate to quantify the fire occurrence possibility. Secondly, the B-RISK model is used to predict and rank the fire severities induced by fire spread. Finally, a priority ranking of fire risk is achieved using the Borda number combining fire occurrence possibility and fire severity. The case study on a typical underwater power station show that the fire occurrence possibility obtained by MAHP is highly consistent with the result of traditional AHP. The B-RISK simulations can identify the fire spread paths and thus the causes of fire expansion. The rankings of fire occurrence possibility and fire severity do not consistent with each other therefore the Borda number can better evaluate the priority of fire risks which builds the foundations for potential fire engineering assessment and design. [ABSTRACT FROM AUTHOR]

This article discusses how the concepts of safety level and safety margin have been approached in recognized peer-reviewed journals within the field of fire safety science. The aim is to explore the scientific efforts that have been made to advocate principles for dimensioning fire safety arrangements in buildings. We restrict our discussion to novel buildings in the sense of lack of similar constructions with relevant long term experience. Due to increasing complexity in buildings, infrastructures, technical systems and society in general, we argue that traditional fire safety science based on natural science principles alone is severely limited. We argue that fire safety and safety margins are emergent properties of socio-technical systems that need to be managed rather than verified. The search for objectivity and mechanistic decision criteria is futile and diverts attention from the main purpose of engineering: to guide decisions during the whole design process and thus enable safe operation. An adapted framework for fire safety engineering is proposed, built around traditional fire safety engineering principles, and founded on constructivist systems theory. The focus is observable quantities and how these quantities can be managed during design and operation of a building project. The framework eases the involvement of stakeholders who are required to consider the safety aspects of the building design. The end goal of fire safety design in our framework is the development of a fire safety control structure that must be enforced to keep systems in a safe state, in which safety margins are deemed sufficient. [ABSTRACT FROM AUTHOR]