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Article
Publication date: 10 April 2017

Negar Elhami Khorasani and Maria E.M. Garlock

This paper aims to present a literature review on the problem of fire following earthquake (FFE) as a potential hazard to communities in seismically active regions. The…

Abstract

Purpose

This paper aims to present a literature review on the problem of fire following earthquake (FFE) as a potential hazard to communities in seismically active regions. The paper is important to work toward resilient communities that are subject to extreme hazards.

Design/methodology/approach

The paper lists and reviews the historical FFE events (20 earthquakes from 7 countries), studies the available analytical tools to evaluate fire ignition and spread in communities after an earthquake, discusses the available studies on performance of individual buildings under post-earthquake fires and summarizes the current literature on mitigation techniques for post-earthquake fires.

Findings

FFE can be considered a potential hazard for urban communities that are especially not prepared for such conditions. The available analytical models are not yet fully up to the standards that can be used by city authorities for decision-making, and therefore, should be further validated. Limited structural analyses of individual buildings under FFE scenarios have been completed. Results show that the drift demand on the building frame increases during post-earthquake fires. Despite the mitigation actions, there are still urban cities that are not prepared for such an event, such as certain areas of California in the USA.

Originality/value

The paper is a complete and an exhaustive collection of literature on different aspects of FFE. Research in earthquake engineering is well advanced, while structural analyses under fire load and performance of communities under FFE can be further advanced.

Details

International Journal of Disaster Resilience in the Built Environment, vol. 8 no. 02
Type: Research Article
ISSN: 1759-5908

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Article
Publication date: 12 September 2016

Negar Elhami Khorasani, Maria Garlock and Paolo Gardoni

This paper aims to develop a framework to assess the reliability of structures subject to a fire following an earthquake (FFE) event. The proposed framework is implemented…

Abstract

Purpose

This paper aims to develop a framework to assess the reliability of structures subject to a fire following an earthquake (FFE) event. The proposed framework is implemented in one seamless programming environment and is used to analyze an example nine-story steel moment-resisting frame (MRF) under an FFE. The framework includes uncertainties in load and material properties at elevated temperatures and evaluates the MRF performance based on various limit states.

Design/methodology/approach

Specifically, this work models the uncertainties in fire load density, yield strength and modulus of elasticity of steel. The location of fire compartment is also varied to investigate the effect of story level (lower vs higher) and bay location (interior vs exterior) of the fire on the post-earthquake performance of the frame. The frame is modeled in OpenSees to perform non-linear dynamic, thermal and reliability analyses of the structure.

Findings

Results show that interior bays are more susceptible than exterior bays to connection failure because of the development of larger tension forces during the cooling phase of the fire. Also, upper floors in general are more probable to reach specified damage states than lower floors because of the smaller beam sizes. Overall, results suggest that modern MRFs with a design that is governed by inter-story drifts have enough residual strength after an earthquake so that a subsequent fire typically does not lead to results significantly different compared to those of an event where the fire occurs without previous seismic damage. However, the seismic damage could lead to larger fire spread, increased danger to the building as a whole and larger associated economic losses.

Originality/value

Although the paper focuses on FFE, the proposed framework is general and can be extended to other multi-hazard scenarios.

Details

Journal of Structural Fire Engineering, vol. 7 no. 3
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 10 December 2013

Behrouz Behnam and Hamid Ronagh

Post-earthquake fire (PEF) is considered as one of the most problematic potentially possible disasters in urban areas, as it may result in a conflagration. Most standards…

Abstract

Post-earthquake fire (PEF) is considered as one of the most problematic potentially possible disasters in urban areas, as it may result in a conflagration. Most standards and criteria, however, ignore the possibility of fire after earthquake and therefore, majority of conventional buildings are not designed to resist thermal loading after an earthquake. Thus, there is high likelihood of rapid collapse for those buildings damaged partially after an earthquake, which are subjected immediately to a following fire. An investigation based on sequential analysis inspired by FEMA356 is performed in this paper on two RC frames; three and five stories at the Life-Safety performance level and designed to the ACI 318-08 code after they are subjected to a spectral PGA of 0.35g. This is followed by a five-hour fire analysis of the weakened structures, from which the time it takes for the damaged structures to collapse is calculated. As a point of reference, the fire resistance is also determined for undamaged structures and before the occurrence of earthquake. The results show that the structures previously damaged by the earthquake and exposed to PEF are more vulnerable than those that are not damaged. A CPEF greater than 1 is then introduced as a function of fire extinguishing or evacuating time that can be multiplied by the base shear at the time of design in order to increase members sizes and thus improve the PEF resistance. Whilst the investigation is for a certain class of structures (ordinary buildings, intermediate reinforced concrete structure, three and five stories), the results confirm the need for the incorporation of post earthquake fire in the process of analysis and design, and provides some quantitative measures on the level of associated effects.

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Article
Publication date: 9 September 2019

Virendra Kumar

The occurrence of multiple hazards in extreme conditions is not unknown nowadays, but the sustainability of the reinforced concrete structures under such scenarios form…

Abstract

Purpose

The occurrence of multiple hazards in extreme conditions is not unknown nowadays, but the sustainability of the reinforced concrete structures under such scenarios form competitive challenges in civil engineering profession. Among all, fire following earthquake (FFE) is categorized under multiple extreme load scenarios which causes sequential damages to the structures. This paper aims to experiment a full-scale RC frame sub-assemblage for the FFE scenario and assess each stage of damage through the nondestructive testing method.

Design/methodology/approach

Two levels of simulated earthquake damages, i.e. immediate occupancy (IO) level and life safety (LS) level of structural performance were induced to the test frame and then, followed by a realistic compartment fire of 1 h duration. Also, the evaluation of damage to the RC frame after the fire subsequent to the earthquake was carried out by obtaining the ultimate capacity of the frame. Ultrasonic pulse velocity and rebound hammer test were conducted to assess the structural endurance of the damaged frame. Cracks were also marked during mechanical damages to the test frame to study the nature of its propagation.

Findings

Careful visual inspection during and after the fire test to the test frame were done. To differentiate between concrete chemically affected by the fire or physically damaged is an important issue. In situ inspection and laboratory tests of concrete components have been performed. Concrete from the test frame was localized with thermo-gravimetric analysis. The UPV results exhibited a sharp decrease in the strength of the concrete material which was also confirmed via the DTA, TGA and TG results. It is important to evaluate the residual capacity of the entire structure under the FFE scenario and propose rehabilitation/retrofit schemes for the building structure.

Research limitations/implications

The heterogeneity in the distribution of the damage has been identified due to variation of fire exposure. The study only highlights the capabilities of the methods for finding the residual capacity of the RC frame sub-assemblage after an occurrence of an FFE.

Originality/value

It is of find kind of research work on full-scale reinforced concrete building. In this, an attempt has been made for the evaluation of concrete structures affected by an FFE through nondestructive and destructive methods.

Details

Journal of Structural Fire Engineering, vol. 10 no. 3
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 13 May 2014

Behrouz Behnam and Hamid Reza Ronagh

Post-earthquake fire (PEF) can lead to a rapid collapse of structures partially damaged by earthquake. As there is almost no established PEF provisions by codes and…

Abstract

Purpose

Post-earthquake fire (PEF) can lead to a rapid collapse of structures partially damaged by earthquake. As there is almost no established PEF provisions by codes and standards, PEF investigations are therefore needed for those buildings. The paper aims to discuss these issues.

Design/methodology/approach

A non-linear PEF analysis comprises three steps, which are the application of gravity loads, earthquake loads and then fire loads. As a fire generally initiates on one floor and then spreads to other floors, applying a sequential fire is more realistic than applying a concurrent fire on several floors. Hence, in this study, the fire is applied sequentially to the floors with a time delay.

Findings

The results indicate a substantial reduction in the resistance of the damaged frame when subjected to PEF. In addition, the results of applying the PEF sequentially is more realistic than the concurrent fire.

Research limitations/implications

It was better to perform an experimental test to have a better understanding of the issue.

Originality/value

PEF can potentially result in a catastrophe in areas located in seismic regions. Thus, investigating the effect of PEF on previously damaged structures is of importance.

Details

International Journal of Structural Integrity, vol. 5 no. 2
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 4 June 2013

Ljupco Lazarov, Meri Cvetkovska and Koce Todorov

Fire following an earthquake is an important factor causing damage to buildings and life-line structures. Therefore, besides satisfying structural design requirements for…

Abstract

Fire following an earthquake is an important factor causing damage to buildings and life-line structures. Therefore, besides satisfying structural design requirements for normal loads, such as dead and live loads including the seismic hazard, buildings should also be designed to withstand the fire following earthquakes for a certain minimum duration as required for a desired level of performance. The behavior of a particular reinforced concrete structure that was fire exposed after seismic action is presented in this paper. The seismic response of the structure is evaluated using a pushover analysis, while the displacement demand under the corresponding seismic event is determined using the recommendations implemented in Eurocode 8.

Details

Journal of Structural Fire Engineering, vol. 4 no. 2
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 19 August 2014

Umesh Sharma, Virendra Kumar, Praveen Kamath, Bhupinder Singh, Pradeep Bhargava, Yogendra Singh, Asif Usmani, Jose Torero, Martin Gillie and Pankaj Pankaj

In present study, a full-scale testing of reinforced concrete (RC) frame sub-assemblage has been investigated under fire subsequent to simulated seismic loading. First…

Abstract

In present study, a full-scale testing of reinforced concrete (RC) frame sub-assemblage has been investigated under fire subsequent to simulated seismic loading. First part of the sequential loading consisted of a quasi-static cyclic lateral loading corresponds to life safety level of structural performance on the test frame. In the second part of the test, a compartment fire was ignited to the pre-damaged test frame for one hour duration simulating fire following earthquake (FFE) scenario. The results showed that the first cracking was observed at the end joints of the roof beams after the frame experienced a 30 mm cyclic lateral displacement. One hour heating and eleven hour cooling was tracked and temperatures were recorded. A knocking sound was heard from the fire compartment after 5 minutes of the fire ignition. An excessive degradation of the concrete material at a number of locations of the frame sub-assemblage was observed during visual inspection after the fire test. The Nondestructive tests (NDT) were also conducted to ascertain the damage in the RC frame at the various stages of loading. The test results developed an understanding of the behaviour of RC frame sub-assemblage in FFE.

Details

Journal of Structural Fire Engineering, vol. 5 no. 3
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 10 June 2019

Farshid Masoumi and Ebrahim Farajpourbonab

The primary purpose of this research was to expand the knowledge base regarding the behavior of steel columns during exposure to fire. This paper presents the numerical…

Abstract

Purpose

The primary purpose of this research was to expand the knowledge base regarding the behavior of steel columns during exposure to fire. This paper presents the numerical study of the effect of heat on the performance of parking steel column in a seven-story steel building under cyclic loading.

Design/methodology/approach

In this research, the forces and deformations developed during a fire are estimated by using detailed 3D finite-element models. The analyses are in the form of a coupled thermo-mechanical analysis in two types of loading: concurrent loading (fire and cyclic loading) and non-concurrent loading (first fire and then cyclically), and the analyses have been conducted in both states of the fire loading with cooling and without cooling using the ABAQUS software. Further, it was investigated whether, during the fire loading, the specimen was protected by a 3-cm-thick concrete coating and how much it changes the seismic performance. After verification of the specimen with the experimental test results, the column model was investigated under different loading conditions.

Findings

The result of analyses indicates that the effect of thermal damage on the performance of steel columns, when cooling is happening late, is more than the state in which cooling occurs immediately after the fire. In this paper, thermal–seismic performance of parking steel columns has been specified and the effect of the fire damage has been investigated for the protected steel by concrete coating and to the non-protected steel, under both cooling and non-cooling states.

Originality/value

This study led to recommendations based on the findings and suggestions for additional work to support performance-based fire engineering. It is clear that predicting force and deformation on steel column during fire is complex and it is affected by many variables. Here in this paper, those variables are examined and proper results have been achieved.

Details

Journal of Structural Fire Engineering, vol. 10 no. 2
Type: Research Article
ISSN: 2040-2317

Keywords

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Article
Publication date: 31 August 2020

Morteza Jamshidi, Heydar Dashti NaserAbadi and Mohammadreza Oliaei

The high heat induced by fire can substantially decrease the load-bearing capacity, which is more critical in unprotected steel structures than concrete reinforced…

Abstract

Purpose

The high heat induced by fire can substantially decrease the load-bearing capacity, which is more critical in unprotected steel structures than concrete reinforced structures. One of the conventional steel structures is a steel-plate shear wall (SPSW) in which thin infill steel plates are used to resist against the lateral loads. Due to the small thickness of infill plates, high heat seems to dramatically influence the lateral load-bearing capacity of this type of structures. Therefore, this study aims to provide an investigation into the performance of SPSW with reduced beam section at high temperature.

Design/methodology/approach

In the present paper, to examine the seismic performance of SPSW at high temperature, 48 single-span single-story steel frames equipped with steel plates with the thicknesses of 2.64 mm, 5 mm and 7 mm and yield stresses of 85 MPa, 165 MPa, 256 MPa and 300 MPa were numerically modeled. Furthermore, their behavioral indices, namely, strength, stiffness, ductility and hysteresis behavior, were studied at the temperatures of 20, 458, 642 and 917? The simulated models in the present paper are based on the experimental specimen presented by Vian and Bruneau (2004).

Findings

The obtained results revealed that the high heat harshly diminishes the seismic performance of SPSW so that the lateral strength is reduced even by 95% at substantially high temperatures. Therefore, SPSW starts losing its strength and stiffness at high temperature such that it completely loses its capacity of strength, stiffness and energy dissipation at the temperature of 917? Moreover, it was proved that by separating the percentage of their participations variations of the infill plate in SPSW, their behavior and the bare frame can be examined even at high temperatures.

Originality/value

To the best of the authors’ knowledge, the seismic performance of SPSW at different temperatures has not been evaluated and compared yet.

Details

Journal of Structural Fire Engineering, vol. 11 no. 4
Type: Research Article
ISSN: 2040-2317

Keywords

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Article
Publication date: 1 January 2000

Eduardo Canabarro, Markus Finkemeier, Richard R. Anderson and Fouad Bendimerad

Insurance‐linked securities can benefit both issuers and investors; they supply insurance and reinsurance companies with additional risk capital at reasonable prices (with…

Abstract

Insurance‐linked securities can benefit both issuers and investors; they supply insurance and reinsurance companies with additional risk capital at reasonable prices (with little or no credit risk), and supply excess returns to investors that are uncorrelated with the returns of other financial assets. This article explains the terminology of insurance and reinsurance, the structure of insurance‐linked securities, and provides an overview of major transactions. First, there is a discussion of how stochastic catastrophe modeling has been applied to assess the risk of natural catastrophes, including the reliability and validation of the risk models. Second, the authors compare the risk‐adjusted returns of recent securitizations on the basis of relative value. Compared with high‐yield bonds, catastrophe (“CAT”) bonds have wide spreads and very attractive Sharpe ratios. In fact, the risk‐adjusted returns on CAT bonds dominate high‐yield bonds. Furthermore, since natural catastrophe risk is essentially uncorrelated with market risk, high expected excess returns make CAT bonds high‐alpha assets. The authors illustrate this point and show that a relatively small allocation of insurance‐linked securities within a fixed income portfolio can enhance the expected return and simultaneously decrease risk, without significantly changing the skewness and kurtosis of the return distribution.

Details

The Journal of Risk Finance, vol. 1 no. 2
Type: Research Article
ISSN: 1526-5943

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