Search results

1 – 10 of over 7000
Article
Publication date: 17 August 2021

Amit Chandra, Anjan Bhowmick and Ashutosh Bagchi

The study investigates the performance of a three-story unprotected steel moment-resisting frame (SMRF) designed for high seismic demand in the fire-only (FO) and post-earthquake…

Abstract

Purpose

The study investigates the performance of a three-story unprotected steel moment-resisting frame (SMRF) designed for high seismic demand in the fire-only (FO) and post-earthquake uniform and traveling fires (PEF). The primary objective is to investigate the effects of seismic residual deformation on the structure's performance in horizontally traveling fires. The traveling fire methodology, unlike conventional fire models, considers a spatially varying temperature environment.

Design/methodology/approach

Multi-step finite element simulations were carried out on undamaged and damaged frames to provide insight into the effects of the earthquake-initiated fires on the local and global behavior of SMRF. The earthquake simulations were conducted using nonlinear time history analysis, whereas the structure in the fire was investigated by sequential thermal-structural analysis procedure in ABAQUS. The frame was subjected to a suite of seven ground motions. In total, four horizontal traveling fire sizes were considered along with the Eurocode (EC) parametric fire for a comparison. The deformation history, axial force and moment variation in the critical beams and columns of affected compartments in the fire heating and cooling regimes were examined. The global structural performance in terms of inter-story drifts in FO and PEF scenarios was investigated.

Findings

It was observed that the larger traveling fires (25 and 48%) are more detrimental to the case study frame than the uniform EC parametric fire. Besides, no appreciable difference was observed in time and modes of failure of the structure in FO and PEF scenarios within the study's parameters.

Originality/value

The present study considers improved traveling fire methodology as an alternate design fire for the first time for the PEF performance of SMRF. The analysis results add to the much needed database on structures' performance in a wide range of fire scenarios.

Details

Journal of Structural Fire Engineering, vol. 12 no. 4
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 23 November 2020

Oliver Bahr

Unbraced one-bay composite frames are an interesting load-bearing structure for buildings with up to three storeys. However, their fire design is demanding given the lack of…

Abstract

Purpose

Unbraced one-bay composite frames are an interesting load-bearing structure for buildings with up to three storeys. However, their fire design is demanding given the lack of simplified design methods. This paper aims to deepen the understanding of the load-bearing behaviour of both unbraced and braced frames when exposed to fire.

Design/methodology/approach

In a previous paper, a numerical model for the fire design of these frames was established and validated with good agreement against fire tests. In the current paper, this model was used to compare the typical differences between braced, semi-braced and unbraced composite frames under fire conditions. Further studies addressed the effect of different heating regimes, i.e. partial fire exposure of the columns in the frames and varying location of the ISO standard fire.

Findings

Numerical investigations showed that it is necessary to take local failure and deformation limits of the fire-exposed frames into account. On this basis, unbraced composite frames can compete with braced frames as they have to endure less thermal restraints than braced frames.

Originality/value

In contrast to other investigations on frames, the numerical model is able to take into account the shear failure, which is especially important within the frame corners. Using this model, it is shown that limited sway is reasonable to reduce thermal restraints and hence local stresses. In this regard, the concept of semi-rigid composite joints with a distinct amount of reinforcement has proven to be very rational in fire design.

Details

Journal of Structural Fire Engineering, vol. 12 no. 1
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 10 January 2018

Oliver Bahr

The purpose of this study is to gain a deeper understanding of the structural behaviour of fire-exposed unbraced composite frames. Designers to date paid little attention to…

Abstract

Purpose

The purpose of this study is to gain a deeper understanding of the structural behaviour of fire-exposed unbraced composite frames. Designers to date paid little attention to unbraced one-bay composite frames as structural system. There are two main reasons for this. First, codes lack simplified methods for the fire design of these frames due to their sway and the linked P-Δ effects when subjected to fire, which complicates the design. Second, it is demanding to construct external composite joints for the regarded one-bay frames. Thus, external joints in composite constructions are mostly constructed as steel joints. Nevertheless, these frames offer advantages. These include increased usable space and flexibility in the building’s use, large spans, fast construction times and inherent fire resistance.

Design/methodology/approach

To profit from these benefits, two different external semi-rigid composite joint were developed for the considered one-bay composite frames. The first solution based on concrete-filled steel tube columns and the second on concrete-filled double skin tube columns. Furthermore, a numerical model was established to study the fire performance of unbraced composite frames. The model was validated against four fire tests on isolated composite joints and two large-scale fire tests on unbraced composite frames.

Findings

Overall, the predictions of the numerical model were in good agreement with the test results. Thus, the numerical model is appropriate for further investigations on the fire performance of unbraced composite frames.

Originality/value

The sequence of construction results in significant stresses in the steel section, which creates difficulties in numerical modelling and may account for the relatively few studies carried out at room temperature. For the fire design, there was, to the best knowledge of the author, to date no numerical model available that was capable of considering the sequence of construction.

Details

Journal of Structural Fire Engineering, vol. 9 no. 4
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 19 April 2024

Mahesh Gaikwad, Suvir Singh, N. Gopalakrishnan, Pradeep Bhargava and Ajay Chourasia

This study investigates the impact of the fire decay phase on structural damage using the sectional analysis method. The primary objective of this work is to forecast the…

Abstract

Purpose

This study investigates the impact of the fire decay phase on structural damage using the sectional analysis method. The primary objective of this work is to forecast the non-dimensional capacity parameters for the axial and flexural load-carrying capacity of reinforced concrete (RC) sections for heating and the subsequent post-heating phase (decay phase) of the fire.

Design/methodology/approach

The sectional analysis method is used to determine the moment and axial capacities. The findings of sectional analysis and heat transfer for the heating stage are initially validated, and the analysis subsequently proceeds to determine the load capacity during the fire’s heating and decay phases by appropriately incorporating non-dimensional sectional and material parameters. The numerical analysis includes four fire curves with different cooling rates and steel percentages.

Findings

The study’s findings indicate that the rate at which the cooling process occurs after undergoing heating substantially impacts the axial and flexural capacity. The maximum degradation in axial and flexural capacity occurred in the range of 15–20% for cooling rates of 3 °C/min and 5 °C/min as compared to the capacity obtained at 120 min of heating for all steel percentages. As the fire cooling rate reduced to 1 °C/min, the highest deterioration in axial and flexural capacity reached 48–50% and 42–46%, respectively, in the post-heating stage.

Research limitations/implications

The established non-dimensional parameters for axial and flexural capacity are limited to the analysed section in the study owing to the thermal profile, however, this can be modified depending on the section geometry and fire scenario.

Practical implications

The study primarily focusses on the degradation of axial and flexural capacity at various time intervals during the entire fire exposure, including heating and cooling. The findings obtained showed that following the completion of the fire’s heating phase, the structural capacity continued to decrease over the subsequent post-heating period. It is recommended that structural members' fire resistance designs encompass both the heating and cooling phases of a fire. Since the capacity degradation varies with fire duration, the conventional method is inadequate to design the load capacity for appropriate fire safety. Therefore, it is essential to adopt a performance-based approach while designing structural elements' capacity for the desired fire resistance rating. The proposed technique of using non-dimensional parameters will effectively support predicting the load capacity for required fire resistance.

Originality/value

The fire-resistant requirements for reinforced concrete structures are generally established based on standard fire exposure conditions, which account for the fire growth phase. However, it is important to note that concrete structures can experience internal damage over time during the decay phase of fires, which can be quantitatively determined using the proposed non-dimensional parameter approach.

Details

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

Keywords

Book part
Publication date: 30 December 2004

Jean L. Dyer

Each of the four objectives can be applied within the military training environment. Military training often requires that soldiers achieve specific levels of performance or…

Abstract

Each of the four objectives can be applied within the military training environment. Military training often requires that soldiers achieve specific levels of performance or proficiency in each phase of training. For example, training courses impose entrance and graduation criteria, and awards are given for excellence in military performance. Frequently, training devices, training media, and training evaluators or observers also directly support the need to diagnose performance strengths and weaknesses. Training measures may be used as indices of performance, and to indicate the need for additional or remedial training.

Details

The Science and Simulation of Human Performance
Type: Book
ISBN: 978-1-84950-296-2

Open Access
Article
Publication date: 17 October 2018

Decheng Li, Tiannian Zhou, Zegong Liu and Jian Wang

The purpose of this study is to investigate the transport phenomena of smoke flow in a semi-open vertical shaft.

1098

Abstract

Purpose

The purpose of this study is to investigate the transport phenomena of smoke flow in a semi-open vertical shaft.

Design/methodology/approach

The large eddy simulation (LES) method was used to model the movement of fire-induced thermal flow in a full-scale vertical shaft. With this model, different fire locations and heat release rates (HRRs) were considered simultaneously.

Findings

It was determined that the burning intensity of the fire is enhanced when the fire attaches to the sidewall, resulting in a larger continuous flame region in the compartment and higher temperatures of the spill plume in the shaft compared to a center fire. In the initial stage of the fire with a small HRR, the buoyancy-driven spill plumes incline toward the side of the shaft opposite the window. Meanwhile, the thermal plumes are also directed away from the center of the shaft by the entrained airflow, but the inclination diminishes as HRR increases. This is because a greater HRR produces higher temperatures, resulting in a stronger buoyancy to drive smoke movement evenly in the shaft. In addition, a dimensionless equation was proposed to predict the rise-time of the smoke plume front in the shaft.

Research limitations/implications

The results need to be verified with experiments.

Practical implications

The results could be applied for design and assessment of semi-open shafts.

Originality/value

This study shows the transport phenomena of smoke flow in a vertical shaft with one open side.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 28 no. 11
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 April 2003

Georgios I. Zekos

Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some…

96086

Abstract

Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.

Details

Managerial Law, vol. 45 no. 1/2
Type: Research Article
ISSN: 0309-0558

Keywords

Article
Publication date: 12 February 2018

Anass Rahouti, Sélim Datoussaïd and Thierry Descamps

This paper aims to focus on the combination of fire- and agent-based modelling approaches to assess the level of safety of a multi-storeyed building case study.

Abstract

Purpose

This paper aims to focus on the combination of fire- and agent-based modelling approaches to assess the level of safety of a multi-storeyed building case study.

Design/methodology/approach

For an existing building to be occupied such as the engineering student dormitory of Mons (Belgium), engineers must establish, among the other things, that the building affords a sufficient level of safety during fire incident. This can be verified in accordance with prescriptive- and performance-based methodologies. The performance-based approach consists on using simulation tools such as fire dynamics simulator with evacuation to ensure/verify the level of safety required. In this paper, a model case study was built and then various scenarios have been implemented to answer some safety questions.

Findings

For this building layout, the results demonstrate that combining different egress components (i.e. stairs and outdoor ladders) has a negative impact on the evacuation process than using only the stairs to evacuate the building; phased evacuation strategy will not necessarily lead to faster evacuation; adding fire doors in the stairs and between the floors has a beneficial effect on the evacuation process.

Originality/value

This case study proposes some recommendations about adapted evacuation strategy and investments to improve the safety of high-rise student’s dormitory in case of fire.

Details

International Journal of Disaster Resilience in the Built Environment, vol. 9 no. 1
Type: Research Article
ISSN: 1759-5908

Keywords

Article
Publication date: 5 June 2023

Abdullah Ehtesham Akbar and Mohammad A. Hassanain

This paper aims to present a systematic review of the published literature on building information model (BIM)-based simulation tools used for occupant evacuation over the past…

Abstract

Purpose

This paper aims to present a systematic review of the published literature on building information model (BIM)-based simulation tools used for occupant evacuation over the past 23 years.

Design/methodology/approach

A literature review was conducted on BIM-based simulation tools used for occupant evacuation over the past 23 years. The search identified a total of 37 relevant papers, which were reviewed. The paper describes the use of BIM-based simulation tools over the years and identifies the research gaps.

Findings

BIM-based simulation tools have undergone progressive development, with constant improvements through the integration of advanced tools and collection of more data. These tools can assist in identifying faults in the building design. The outcomes of the simulation were not entirely accurate, as real-life scenarios vary depending on the various building types and the behavior of their occupants.

Research limitations/implications

This study contributes to the literature through reviewing the capabilities of BIM-based simulation tools and the different simulation methods along with their limitations.

Practical implications

Fire safety engineers and architects can comprehend the utilization of BIM-based simulation tools to enhance the fire evacuation in light of their shortcomings and flaws.

Originality/value

BIM-based simulation tools are becoming more advanced and widely used. There has not been a comprehensive evaluation of the capabilities of the integration of BIM tools and simulation modeling for occupant evacuation. This study guides researchers on the capabilities and efficiencies of integrated solutions for occupant evacuations and their inherent shortcomings. The study identifies future research areas in BIM-based tools for occupant evacuation.

Details

Facilities , vol. 41 no. 9/10
Type: Research Article
ISSN: 0263-2772

Keywords

Article
Publication date: 1 September 1999

Jonathan D. Sime

This paper reviews the human behaviour and risk communications which occurred during a number of major fires (Beverly Hills Supper Club, Summerland, Woolworth’s, Bradford, King’s…

5328

Abstract

This paper reviews the human behaviour and risk communications which occurred during a number of major fires (Beverly Hills Supper Club, Summerland, Woolworth’s, Bradford, King’s Cross) and a crowd crush (Hillsborough). The paper draws on official Inquiry reports and related research, including a series of five underground station evacuation studies modelled on the King’s Cross fire scenario. The pattern of delay in warning the public is considered in terms of misconceptions about “panic” and the performance of public facilities as a communication system consisting of design, technology, management and occupancy (setting in use). The paper advocates performance‐based design, warning system technology and facilities management (organisational and occupant response) criteria, allied to minimally sufficient early warning of the public on a risk communication timeline. The latter needs to address and accommodate the timing and duration of occupant response, shelter and escape behaviour from different locations as an emergency unfolds.

Details

Facilities, vol. 17 no. 9/10
Type: Research Article
ISSN: 0263-2772

Keywords

1 – 10 of over 7000