Fire Safety Engineering Approach Research Articles

A fire safety engineering approach to improving community resilience to the impacts of wildfire

AbstractEach year severe wildfires continue to cause significant destruction resulting in the loss of life, property, critical infrastructure, and the environment. In an effort to increase community preparedness and resilience to wildfire, international jurisdictions have adopted both guiding principles and prescriptive codes that apply to both urban planning and fire engineering design of buildings within the wildland–urban interface. These measures are intended to protect occupants, enhance the survivability of structures from different fire exposure mechanisms, and increase the chances of successful firefighting operations. However, research has identified (i) inconsistent approaches to regulation and governance; (ii) limited research on which urban design and building standards are based; and (iii) misaligned or contradictory urban design and building standards. This not only stifles the use of development proposing suitable performance‐based design that could achieve the required outcomes but can increase administrative burdens and development costs without increasing safety. The aim of this current study is to contribute to addressing identified shortfalls by identifying and distilling the last 23 years of research in the field related to (i) the development of evidence‐based performance requirements, and (ii) the application of effective governance arrangements in order to enhance urban design and wildfire engineering practices. These aims are achieved through a systematic literature review. Ultimately, however, of the 608 initial articles captured in the identification phase of the SLR, not a single article provided insight into the most effective regulatory or governance mechanism, and only three provided criteria suitable for adoption as a performance requirement. While the aims of this study were only partially achieved, it does provide a foundation for the field by way of identifying and distilling the current state of practice.

Natural Ventilation of Smoke Subject to Wind Pressure Within Fire Safety Engineering Approach

This paper presents an analytical model able to explore the design method of natural smoke evacuation through an exhaust vent subject to wind pressure. The proposed model can be used to determine the flow rate of smoke and the optimal section of the exhaust vent according to the geometric parameters of the room, the heat release rate and the pressure exerted by the wind forces at the exhaust vent. The numerical resolutions of the mathematical equations of the model were performed using the dichotomy method. The proposed analytical approach is built progressively by, (i) the examination of interaction forces between buoyancy forces and wind pressure forces, (ii) a numerical validation of the analytical model using the numerical simulation software Fire Dynamics Simulator, and (iii) proposal of a method of approximation of the optimal section of the exhaust vent for a maximum smoke evacuation rate. The results show very satisfactory and provide adequate prediction of the optimal size of the exhaust vent between the theoretical approximation and various configurations of numerical simulation. The feasibility and effectiveness of the proposed approach lead to an accurate and reliable analytical model able to analyze the influence of the size of natural smoke evacuation vents subjected to the pressure of wind forces.

Inverse heat transfer modeling applied to the estimation of the apparent thermal conductivity of an intumescent fire retardant paint

Intumescent paints are widely used as passive fire protective materials in the building sector, primarily with regard to steel framed structures. The fire resistance of commercial intumescent coatings is typically tested experimentally using expensive and time consuming large-scale tests; conversely, the increasingly common performance-based fire safety engineering approach requires the development of techniques to generalize and predict the behavior of these protective materials. Recently, an experimental and data processing technique based on temperature measurements of the growing char layer and on the formulation of the inverse heat conduction problem within the system, has been proposed. This investigation indicated that an accurate and complete modeling approach is required to make robust predictions in the processing of the experimental data. In this paper, an enhanced procedure for estimating the apparent thermal conductivity of the intumescent paint is proposed and validated. The analysis presented in this study, performed with a physical and chemical characterization of the intumescent paint, allows estimation of the apparent thermal conductivity of the char layer with good approximation, thereby providing important information for assessing the fire protective capability of the coating under the fire safety engineering approach.

22.01: Fire and seismic assessment of an existing steel‐concrete composite structure

ABSTRACTAn existing steel‐concrete composite structure is analyzed in order to assess its level of protection against both fire and earthquakes. The building has been designed and built more than thirty years ago, implying that both these hazards may not be adequately verified with respect to the current codes. As concerns the fire protection, intumescent coating (IC) was applied on steel members, while an original passive energy dissipation system was employed against seismic actions. In particular, special devices were introduced to sustain the floors, which are suspended at reticular beams on the top of concrete pillars. A Fire Safety Engineering approach has been adopted to assess the structural resistance to fire. To define the thermal properties of the protective, experimental tests were carried out on the existing IC and a new IC. Moreover, thermomechanical analyses of the existing steel structure were carried out, under different fire scenarios, selected according to the fire risk of the different occupancy class of the structure. Non‐linearities and large displacements effects were taken into account. The seismic structural response has been investigated by implementing a dynamic nonlinear analysis according to the current Italian Code. In particular the seismic passive protection system, consisting in dissipative hysteretic devices combined with isolators, has been modelled as a parallel elastic and elasto‐plastic springs' system. Mechanical parameters adopted for the analyses are the result of a wide bibliography study.

Application of criteria for selecting fire scenarios for structures within fire safety engineering approach

This paper deals with a crucial aspect of the application of Fire Safety Engineering (FSE), which is the definition of fire scenarios and the choice of the design ones for structures. FSE requires, moreover, the choice of performance levels, fire models and, generally, advanced thermo-mechanical analyses.The number of possible fire scenarios is usually too large and the analysis of each one is not practicable. Therefore, the design fire scenarios should be chosen, in order to analyse the most severe cases for the structure.The choice of the design fire scenarios could be carried out through two possible procedures, shown in this paper: a) the Fire Risk Assessment (FRA), whereby a proper estimation of the Risk associated to each fire scenario is conducted; b) the procedure proposed in EN1991-1-2 (Annex E), whereby a single group of design fire scenarios is defined, taking into account the phenomena capable to modify the fire development, by introducing some coefficients in the calculation of the fire density load.In this paper, the main concepts of the two methodologies are shown and discussed and a comparison is proposed referring to a case study, inspired to an existing office building.

Fire safety engineering applied to high-rise building facades

Fire safety of high-rise building facades is a complex problem, therefore the use of prescriptive fire codes could not be sufficient to ensure a proper building fire safety level. In new high rise buildings the fire safety of facades can be taken into account by means of performance based fire design that can help in the selection of the best technological solutions and material choices. This article deals with a case study done on the Piedmont Region Headquarters (TORRE REGIONE PIEMONTE) which is one of the highest office buildings in Italy. The Torre Regione Piemonte is located in Turin and has 45 storey and a total height of 183,61 m. The building is characterized by the closed enclosure called Grand Space which is continuous for almost the entire height of the building and contains volumes such as offices/meeting rooms named as Satellites. In order to fulfil Italian fire safety requirements, the Torre Regione Piemonte building has been assessed using the performance base design and fire safety engineering approach. This paper deals with the design process selection of the most representative fire scenarios focusing on the fire resistance performance requirements of structural and glazed elements of the facades. Furthermore, all the simulation, calculations and performance fire resistant requirements of the high rise building have been supported by specific laboratory tests and experimental results, that are reported and discussed within paper. © Owned by the authors, published by EDP Sciences, 2016 Language: en

Relationship between the design height of the shelves in industrial warehouses and their heat release rate

In the last decades, fire safety engineering (FSE) has been extensively used to improve the design of many industrial systems. In this study, the FSE approach is applied to determine the optimal vertical distance between pallets allocated in a warehouse containing plastic materials in order to control and reduce typical fire parameter such as the heat release rate (HRR). Moreover, the study reported in this paper is used to confirm that the design rules indicated by current EN norms for automated fire extinguishing systems are well effective to limit the fire risk and ensure proper safety conditions.

Fire Safety Engineering for Open and Closed Car Parks: C.A.S.E. Project for L’Aquila

The Fire Safety Engineering (FSE) is a multi-discipline aimed to define the fire safety strategy for buildings under fire conditions, in which structural stability and control of fire spread are achieved by providing active and/or passive fire protection. In this paper, the aspects of FSE for the structural safety checks in case of fire are shown with reference to Italian and European standards. FSE requires the choice of a performance level, the definition of design fire scenarios, the choice of heat flows models and several numerical thermo-mechanical analyses. The information provided by a significant research, performed in Europe for open and closed car parks, are used to apply the FSE to the car parks of the new buildings of the C.A.S.E. Project for L’Aquila, characterized by steel columns supporting the seismically isolated superstructure. The results of the application of the FSE approach are reported and discussed in the second part of the paper.

An evacuation model: the SGEM package

The United Kingdom, New Zealand, Australia, Sweden, Hong Kong and many other developed countries are moving away from the prescriptive-based building/fire codes and towards performance-based approaches. Designers adopt a fire safety engineering approach to provide rational design on the basis of performance criteria. One of the major issues in fire safety engineering design refers to the design of the escape system. It can be regarded as the skeleton of many fire safety engineering designs, in particular for the evaluation of life safety of occupants. In view of the complexity of modern buildings, it is difficult to model the escape pattern of the occupants by simple calculations. With the advancement of digital computers, many researchers have recently developed computer-based evacuation models. For modern complex buildings, it may be time-consuming to develop the input for simulation. This article describes an evacuation model—spatial-grid evacuation model (SGEM), which includes a pre-processing engine to assist in the transformation of the spatial information from computer-aided design (CAD) based architectural plans and perform a simulation to generate the escape patterns in many complex buildings. This model resolves the setting of a building into a network with a series of nodes. Each node consists of a loop (an open-loop) representing enclosed spaces with at least one opening that serves as an arc of the network, and other close-loops, which represent obstacles, can exist in the open-loop. The geometrical and spatial information captured from CAD plans will be integrated with the simulator, and the movement of evacuees is solved by a series of difference equations, within a finite grid that is generated within a node. The trajectory of each individual is recorded and the evacuation pattern will be visualized under the AutoCAD environment. In addition, a crowd flow function which has been generated by a gas-lattice model is adopted in the model.

An Investigation on the Building Officials' Perception for the Use of Performance-Based Fire Engineering Approach in Building Design

Traditionally, the spatial design of a building is influenced by the prescriptive fire safety codes. As buildings develop and become more complex and new materials are used, the prescriptive fire safety rules may not provide an efficient solution to the new building design. A system approach to the design of fire safety in buildings on the basis of performance criteria may be necessary. The recently published fire codes in Hong Kong have recognized the use of a performance-based fire safety engineering approach as a means to demonstrate the adequacy of fire safety design in a building. However, the judgement on the adequacy is made by the building control officials. Whether they believe the use of such a performance-based fire safety engineering approach can provide adequate fire safety level in a building can have influence on promoting performance-based design. This paper discusses the Hong Kong system and a survey on the views of the building control officials. The investigation indicates that the officials, in general, agree with the need of using performance-based approach, in particular to keep pace with the advancement of building technology. However, they have reservations on the adequacy of current tools for fire safety engineering design. Such views are in line with that of the building officials in the United States.

Fire engineering design of steel structures

AbstractThis article reviews progress in the fire engineering design of steel structures. The problems associated with the tradiational prescriptive methods of achieving regulatory compliance are identified. The concept of a fire safety engineering approach to design is discussed in relation to the structural performance of complete buildings in fire and the development of analytical models to predict structural response at elevated temperature. Full‐scale tests, observations from real fires and predictive models have all indicated that the fire resistance of complete structures is significantly better than that of the single elements from which fire resistance is universally assessed. Recent full‐scale tests on an eight‐storey steel framed building with composite floors have attempted to identify the alternative load paths which provide this enhanced performance and to quantify the present factors of safety. These tests are described in some detail. Conclusions are drawn from previous experience and current research, and directions for future research efforts are identified.