Authors: Mozhdeh Shoaei, R. Maddahin, H. Afshin, B. Farhanie
Abstract: Development of cities as well as population growth causes to development of public transportation especially subway lines. The high capacity besides the high speed in transportation makes them the popular transportation system. Fire is the one of the most important issues that may occur in subways. The difference in flame size, emissionheat, smoke and pollutants generation of subway fires attracts an especial attention of fire investigators. The emergency ventilation of subways in the case of fire should have the ability of discharging heat, smoke and pollutants from passenger escape route and preparing a safe place for a specific duration. The optimal performance of emergency ventilation system has a close relation with fire scenarios. In this research the fire scenarios of Tehran subway are designed based on regional approach. In order to show the performance of ventilation systems in emergency mode, the fire scenarios are simulated using computational fluid dynamics. Simulations are conducted for steady and unsteady modes. In transient simulations, a fast t2 growth curve is used for the heat and smoke release rate. Simulation results show that new regional scenarios could provide safe escape routes to evacuate passengers during the fire.
983
Authors: Ran Bi, Yong Jun Liu, Yu Min Yan, Li Hong Yao
Abstract: Analysis the fire behavior of the reinforced concrete frame structure from three aspects: the fire scene simulation, the temperature distribution and the deformation calculation of structure. Applying the actual temperature curves based on fire simulation software FDS to finite element analysis software ANSYS, get the temperature distribution and the deformation of structure under fire. Results show that structure will be destroyed because of the beams under fire are reaching the fire resistance, and the calculation results can meet the requirement of specification. Finally, the practical application shows the feasibility of getting the temperature-time curves with FDS instead of the international standard temperature-time curves for fire process analysis.
1024
Authors: Constantin Sorin Scutarasu, Dan Diaconu-Şotropa, Marinela Barbuta
Abstract: Important goals in the fire safety design, such as preventing loss of life and goods damage, are achieved by maintaining the stability of structures exposed to fire for a period of time established by norms and standards. Real fire scenarios confirm that the specific technical regulations which actually have a prescriptive character (both national and international) do not deal with sufficient possibilities regarding the assessment of structural fire safety. The new approach on structural safety, based on engineering notions, gives us additional prospects on it and it is included in the issues of the fire safety design of structures. A relatively new field of study, known by a few professionals focused on fire safety (but well acknowledged in the research area), fire safety design met with lots of changes and restructuring of the governing concepts and procedures and of the information with which they operate, due to the fast accumulation of experience in this area of engineering activity. Consequently, after countries such as Australia, Canada, New Zeeland or USA provided towards professionals specific technical regulations for fire safety design, groups of experts in these aforementioned countries have joined their forces to try to diminish the differences that exists between those regulations and to give a unitary character to them, a better conceptualized engineering approach of the fire safety design. The result: occurrence of the publication International Fire Engineering Guidelines (last edition from 2005). The systematic approach of fire safety design in constructions pointed, once again, the possibility of modular organization of this field of study, the relations between modules being established according to the objective or objectives in the fire safety design for a specified building. This article aims to put forward, from this modularized perspective, the study of the fire safety design of a building exposed to fire; hence, the practical part of the article exhibits the numerical simulation of initialization and development of the fire process for a large scale religious building. The main features of the building represent the amount of space that facilitates the spreading of smoke and warm gases and which increases the risk of damaging the structural reinforced concrete elements. Application calls to specific numerical simulation with a higher degree of credibility, such as those realized by the FDS (Fire Dynamics Simulation) software.
102
