A sensitivity matrix method to understand the building fire egress performance gap

Comparison of sensitivity matrix method, power function-based response surface method, and artificial neural network in the analysis of building fire egress performance

Time-dependent fire risk assessment for occupant evacuation in public assembly buildings

A probabilistic ASET (Available Safe Egress Time)/RSET (Required Safe Egress Time) timeline assessment approach is presented to make uncertainty analysis on number of fatalities in building fires. ASET and RSET are achieved as two dependent random variables with consideration of uncertainties of fire dynamics and human behaviors. When analyzing stochastic ASET, uncertainty of design fires is considered by coupling Monte Carlo simulation with two-zone fire model. When analyzing stochastic RSET, uncertainty of fire detection and alarm time is considered by coupling fire model and Monte Carlo simulation. Occupant pre-movement time is proposed as probability distribution. The interdependency between ASET and RSET is considered in the analysis process by lognormal fire growth rates. To demonstrate the approach, a case study is discussed.

최근 실내 공간에서의 재난, 화재와 테러 등 대피상황을 재현하여 이를 가시화하기 위한 연구가 주목 받고 있으며, 실내 공간에 대한 모델을 설계하고 인명 안전 평가를 통한 신뢰성 있는 분석이 요구되고 있다. 이에 본 연구에서는 실제적인 건물 화재 위험 요인을 고려하여 피난 안전성 분석과 피난 경로 안내가 가능한 시뮬레이션 모델을 개발하고자 하였다. 이를 위해 인천터미널역 역사를 대상으로 3차원 화재 및 피난 모델을 설계하고, 실내 내장재의 재질을 바탕으로 열 매개변수와 화재 인지 장치를 이용하여 화재 위험 분석을 수행하였다. 둘째, 인명안전을 위한 평가에 있어 화재 시뮬레이션인 FDS(Fire Dynamics Simulator)와 피난 시뮬레이션을 통해 재실자가 인체에 손상 없이 견딜 수 있는 피난허용시간(ASET: Available Safe Egress Time)을 산출하였다. 또한 화재를 감지하고 안전한 장소까지 완전하게 피난하는데 소요되는 피난요구시간(RSET: Required Safe Egress Time)을 계산하고 이를 비교 분석하였다. 결과적으로 연구대상의 3차원 공간적인 정보를 기반으로 한 실내 공간 모델과, 고시된 안전기준을 반영한 열차 내 화재 및 피난 위험도 측정 시뮬레이션 분석을 통해 보다 실제적인 안전성 평가를 수행 할 수 있었다. Recently, the research to visualize and to reproduce evacuation situations such as terrorism, the disaster and fire indoor space has been come into the spotlight and designing a model for interior space and reliable analysis through safety evaluation of the life is required. Therefore, this paper aims to develop simulation model which is able to suggest evacuation route guidance and safety analysis by considering the major risk factor of fire in actual building. First of all, we designed 3D-based fire and evacuation model at a subway station building in Incheon and performed fire risk analysis through thermal parameters on the basis of interior materials supplied by Incheon Transit Corporation. In order to evaluate safety of a life, ASET (Available Safe Egress Time), which is the time for occupants to endure without damage, and RSET (Required Safe Egress Time) are calculated through evacuation simulation by Fire Dynamics Simulator. Finally, we can come to the conclusion that a more realistic safety assessment is carried out through indoor space model based on 3-dimension building information and simulation analysis applied by safety guideline for measurement of fire and evacuation risk.

This fire and life safety analysis was performed on the Grant M. Brown Engineering Building in order to determine if the building meets the life safety goals set forth by a prescriptive and performance based analysis. This building was built to a strict set of codes and standards. For the prescriptive analysis the buildings egress design, fire detection and alarm systems, fire sprinkler system, occupancy classification, construction type, and structural fire protection are evaluated in terms of the life safety of the occupants. In the performance based design analysis four computer based programs were used to model egress and fire simulated conditions. These models produced outputs that could be compared to tenability limits for the occupants to determine if the Available Safe Egress Time (ASET) was longer than the Required Safe Egress Time (RSET). In the first design fire scenario a sofa located off the main exit corridor ignites. At 240 seconds the tenability limit for visibility is reached, setting the Available Safe Egress Time (ASET). Full evacuation of the building is accomplished by 191.5 seconds, leaving a margin of 48.5 seconds before conditions become untenable. This building passed the performance based design criteria for maintaining tenability of the occupants during the complete egress of the building. In the second design fire scenario a set of office storage cabinets located under the main exit stairs on the east side ignites. At 180 seconds the tenability limit for visibility is reached, setting the Available Safe Egress Time (ASET). Full evacuation of the building is accomplished by 252.3 seconds. This evacuation time is more than the first scenario because the stairs become unusable in terms of visual tenability 60 seconds after the start of the fire and thus forcing the second story occupants to have to use only the remaining stairs on the west side of the building. The Available Safe Egress Time does not exceed the Required Safe Egress Time. This building fails the performance based design criteria for maintaining tenability of the occupants during the complete egress of the building. The end of this analysis makes recommendations on how to improve the buildings fire safety from the results found in the study.

Large railway interchange stations with complex geometry are common in contemporary integrated railway networks. Fire evacuation is commonly designed using the timeline analysis in comparing Available Safe Egress Time (ASET) and Required Safe Egress Time (RSET) with agreed scenarios. Smoke management systems are required to achieve longer ASET. Egress time analysis will be evaluated in this paper for a typical large railway interchange. The fire environment was simulated using fire dynamics simulator (FDS), a software based on computational fluid dynamics (CFD). Design fires of 2, 2.5, 5, 10, 25 and 50 MW were used in estimating ASET. Egress simulations by the software SIMULEX were conducted to predict the RSET under passenger loadings of 0.5, 1, 2 and 4 m2/person. The results show that the ASET in most of the cases with higher fire size and with higher passenger loading are less than the RSET. Consequently, the passengers are unsafe in the event of fire evacuation. Therefore, a larger safety margin, defined as the difference between ASET and RSET, should be provided. In the case of low safety margin in some existing stations, fire safety management and procedures on handling fire incidents have to be reformulated properly and carefully.

In the discipline of fire engineering, computational simulation tools are used to evaluate the available safe egress time (ASET) and required safe egress time (RSET) of a building fire. ASET and RSET are often analyzed separately, using computational fluid dynamics (CFD) and crowd dynamics, respectively. Although there are advantages to coupling the ASET and RSET analysis to quantify tenability conditions and reevaluate evacuation time within a building, the coupling process is computationally complex, requiring multiple steps. The coupling setup can be time-consuming, particularly when the results are limited to the modeled scenario. In addition, the procedure is not uniform throughout the industry. This paper presents the successful one-way coupling of CFD and crowd dynamics modeling through a new simplified methodology that captures the impact of fractional effective dose (FED) and reduced visibility from smoke on the individual evacuee’s movement and the human interaction. The simulation tools used were Fire Dynamics Simulator (FDS) and Oasys MassMotion for crowd dynamics. The coupling was carried out with the help of the software development kit of Oasys MassMotion in two different example geometries: an open-plan room and a floor with six rooms and a corridor. The results presented in this paper show that, when comparing an uncoupled and a coupled simulation, the effects of the smoke lead to different crowd density profiles, particularly closer to the exit, which elongates the overall evacuation time. This coupling method can be applied to any geometry because of its flexible and modular framework.

This study implements Building Information Modeling (BIM) for conducting a simulation design involving the technologies of Fire Dynamics Simulator (FDS) and Agent Based Modeling (ABM) to foresee the relationship between evacuators’ mortality and building layout design. The goals of this paper are to investigate (1) how to predict the building’s Available Safe Egress Time (ASET) by using FDS software; (2) how to reflect the evacuation behavior within an ABM simulation; (3) how would the Required Safe Egress Time (RSET) be impacted by the building properties, fire properties, and human behavior. By making a comparison between ASET and RSET, the optimized building layout design that reflects minimum RSET can be chosen. And finally, BIM serves as the environment to visualize the results of (1) the hazardous zones that reflected in the fire simulation; (2) the effective escape routes that are recommended by the evacuation scenario. These results can be used to improve fire safety management for both fire education and construction design. Following the results, this paper concludes with a description of challenges associated with building fire and agent-based evacuation simulations that would arise from developing a BIM-based framework for highly occupied building fires.

Assessing life safety by comparing the available safe egress time (ASET) and the required safe egress time (RSET) is a prominent task in performance-based fire safety design. The calculation of a safety margin by subtracting RSET from ASET is a straightforward concept and is easy to understand. However, when the concept was developed, fire and evacuation models only provided punctual information derived from experimental correlations or hand calculations. Nowadays, complex computer models for fire and evacuation dynamics have become state of the art. However, the ASET-RSET concept has not adapted to these developments. While uncertainties related to the model input and the model application are widely recognised, uncertainties emerging from analysing the output only play a subordinate role.Therefore, we introduce a map representation of ASET and RSET. The maps are generated by a spatial evaluation of the quantities used to determine ASET and RSET. Based on that, a difference map is introduced to represent the safety margin throughout the entire domain. Finally, a method is proposed to reduce the high information content of the difference maps to one scalar measure of consequences. This facilitates multivariate or risk-based analysis approaches and thus is able to reduce the uncertainties in performance-based design.

This study evaluates evacuation safety by conducting a simulation of toxic effects, which are hazardous to one’s health, in surrounding areas — such as that of hazardous materials manufacturing plants — due to hydrogen cyanide leaks. This study then proposes alternatives in areas that do not adequately address evacuation safety. For casualties due to hydrogen cyanide leakage accidents, Available Safe Egress Time (ASET) was calculated using the Areal Locations of Hazardous Atmospheres (ALOHA), an off-site impact assessment program, while the RSET (Required Safe Egress Time) was calculated using Pathfinder, an evacuation simulation program. Evacuation safety was evaluated by comparing ASET and RSET. Using the ALOHA program, the time taken to reach the AEGL-2 concentration was evaluated for each of the 12 scenarios. The Pathfinder program was used to evaluate the total evacuation time for high-rise apartments. The ASET of 3 out of the 12 accident scenarios was greater than that of the RSET. In the remaining nine accident scenarios, evacuation safety was not secured because the ASET was smaller than that of the RSET, whereas evacuation safety increased as the horizontal distance from the leak point increased. Because evacuation safety is not guaranteed in high-rise apartments, hazardous material safety management that reflects health risks, performance-based design for apartments less than 10 km from the industrial complex boundary, strengthening of evacuation safety zones, and RSET surcharges are required depending on the size of specific fire objects.

ABSTRACTA green railway station adopting natural ventilation was built in Hong Kong to promote sustainable architectural design. Similar to many other green or sustainable projects, such design failed to comply with the local fire safety codes. There are potential fire hazards due to the adopted green features. Better ventilation provision would supply more air to burn the combustibles in case of fire. Performance‐based design was applied using the timeline analysis to determine the fire safety provisions. In this paper, fire simulations were carried out to predict the available safe egress time (ASET) under low design fires with smoke toxicity including only the carbon monoxide concentration. Evacuation simulations were conducted to predict the required safe egress time (RSET) under low passenger loadings. Studies on human behaviour under big fires and heavy passenger loadings were not included. Problems to be encountered in this green railway station using the timeline analysis will be pointed out in this paper. ASET was estimated by computational fluid dynamics with bigger fires resulted from the green features. RSET was estimated by evacuation software under local passenger loadings. The results indicated that ASET are less than RSET under big fires with heavy passenger loadings. Copyright © 2013 John Wiley & Sons, Ltd.

The purpose of the culminating report was to perform a prescriptive-based and performance-based analysis on the fire and life safety systems in the laboratory building at Sandia National Laboratories (SNL). The prescriptive-based analysis determined if the laboratory building met applicable code requirements for life safety systems. The performance-based analysis conducted a series of fire scenarios to ensure the fire and life safety systems provided adequate egress time for occupants in the event of a fire. The prescriptive-based analysis was based on the Life Safety Code (LSC) and International Building Code (IBC). The laboratory building is a mixed occupancy building. The occupancy of each area was classified according to the use of the area and the hazards that exist. The code was used to determine if the life safety systems were appropriate for each occupancy classification. Life safety systems include: egress, fire suppression, fire alarm, and structural fire protection. The capacity of the egress system was calculated and compared to the occupant load. Analysis of the fire suppression system determined if the automatic sprinkler system was built to National Fire Protection Associate (NFPA) standards. The sprinkler water demand was calculated to ensure the water supply to the building was adequate. The fire alarm system was analyzed for proper spacing of detection and notification appliances. The electrical demand of the alarm system was calculated to ensure the battery backup supply was sufficient. The structural fire protection analysis confirmed proper materials and separation requirements existed in the building. The performance-based analysis used stakeholders’ goals and objectives to select appropriate fire scenarios to test the ability of the fire protection systems. The first fire scenario was a lobby fire open to the main corridor with ineffective sprinklers. The second scenario was a portable heater fire that ignited an office workstation. The third scenario was a flammable liquid spill fire located in a high hazard area. The Society of Fire Protection Engineers (SFPE) hydraulic model, DETACT, and Pathfinder were used to calculate the required safe egress time (RSET). Fire Dynamics Simulator (FDS) was used to calculate the available safe egress time (ASET). A fire scenario was considered successful if the ASET was greater than the RSET. A qualitative risk analysis was performed in order to provide a list of prioritized recommendations to achieve a successful fire scenario. The laboratory building complied with all aspects of the prescriptive-based analysis except for having an adequate water supply.

A fire protection and life safety analysis of the Henderson Engineers, Inc. (HEI) building in Lenexa, KS (Kansas City) is performed. Both prescriptive and performance-based methods have been used to evaluate the building against the codes and standards of the 2012 International Building Code (IBC). The following prescriptive fire protection and life safety systems were analyzed: Occupancy Classification, Building Construction Type, Fire Protection Features, Structural Fire Protection, Fire Barriers, Automatic Fire Sprinkler System, Fire Alarm System, and Means of Egress During the prescriptive approach, the following deficiencies were identified: 1) As-builts indicate a horizontal assembly fire-resistance rating of only 1-hour, while shafts in the building are 2-hour fire-resistance rated, 2) Fire alarm notification devices are missing/over-spaced throughout the building, and 3) Occupant load exceeds egress capacity on the 3rd Floor, and total building occupant load exceeds total building egress capacity. A performance-based analysis of the HEI building is performed. The evaluation involves the evaluation of a design fire scenario that accounts for an increased occupant load and the elimination of an exit. This scenario is modeled using Pathfinder, Pyrosim, and Fire Dynamics Simulator (FDS). The tenability results of the simulation are compared to the established tenability thresholds to determine the available safe egress time (ASET) for each scenario. This time is compared to the required safe egress time (RSET) defined by a pathfinder simulation for the increased occupant load to egress from the floor in the design fire scenario. The fire scenario evaluated an upholstered couch fire in a small room. RSET was calculated as 500 seconds and ASET was determined to be 160 when the visibility tenability criteria is exceeded. However, this result does not necessarily confirm that ASET

This report is a Life Safety Analysis of the XYZ building in Colorado. It is a government contract facility and as such prefers that its real name and location not be utilized for this report. The building was assessed prescriptively using the 2009 International Building Code (IBC) and was found to be predominantly compliant with the code and the relevant referenced standards. The building was then assessed using a Performance Based Design in accordance with methodologies found and addressed in common fire protection literature. The Design Criteria chosen to determine tenability for the Required Safe Egress Time (RSET) were Carbon Monoxide of 1200 ppm, Visibility of 6 meters, Temperature of 60°C and a Smoke Layer Height of 2 meters off the floor. Two Design Fire Scenarios were used to assess whether the tenability criteria could be met within the Available Safe Egress Time (ASET). The first fire was situated in the storage area of the shipping and receiving area. This was considered the highest challenge fire in the building. The second fire was a common office fire located on the 2nd floor as distal as possible from a means of egress. Fire Dynamics Simulator (FDS) and Smokeview were utilized to assess the time for the Design Criteria to be met and thus the ASET. Additionally, various calculations were performed by hand using formula obtained from the above referenced sources to calculate egress times and the RSET. All tenability criteria were met within the RSET with the exception of the Smoke Layer height, which failed by approximately 3 minutes in the office fire scenario and failed by 1 minute in the shipping area fire.

In recent years, the number of studio residential buildings has increased significantly in Korea, as well as in many other countries, due to changes in living patterns. In Korea especially, there have been many fire accidents in studio residential buildings, which have caused a huge number of casualties and property damages, because the buildings were not adequately equipped for firefighting. In this study, the egress safety of a typical studio residential building in Korea is analyzed. Fire simulations were performed with variables of the fire location and the capacity of the smoke exhaust system to estimate the available safe egress time (ASET); egress simulations were also performed with the variable of egress delay time, and the required safe egress time (RSET) was determined. Then, the egress safety was evaluated, and the criteria for egress safety evaluation were proposed based on the simulation results. A studio residential building with a floor plan different from the prototype was used to validate the proposed egress safety criteria. Finally, a simple evaluation model is presented to estimate the required safe egress time (RSET) without simulation and to examine the impact of bottlenecks.