Reliable assumptions for structural fire design of steel car parks

PurposeThis study aims to analyze and discuss the key design assumptions needed for design of car parks in steel, to highlight the impact that the increased fire loads introduced by modern cars and changes in the fire dynamics have on the design, such as fire spread leading to non-localized fires.Design/methodology/approachIn particular, a reliable fire load density to be used for structural design of car park structures is assessed, based on investigations of the fire loads of modern cars. Based on knowledge of fire load and fire performance of cars, the consequences on the fire safety design of steel structures are presented.FindingsDesign recommendation about fire load density and fire protection of common steel profiles are given. Finally, the proposed design is compared with a design practice that has been applied in many instances for car parks constructed with unprotected steel, and recommendations for a reliable design process are provided.Originality/valueNumerous car park buildings have recently been designed of steel structures without passive or active fire protection. The key assumptions that makes possible such design are local fire scenarios, outdated values of the car fire load and utilization of the ultimate steel strength. This paper identifies the shortcomings of such key assumptions, indicating the need for revisiting the methods and possibly even checking the analyses carried out for some already-built car parks.

Improvement of the Assessment Method for Fire Resistance of Steel Structures in the Temperature Regime of Fire under Realistic Conditions

There was researched the influence of fire temperature regimes, obtained by the proposed mathematical models, on the mechanical characteristics of metal structures. As a result, the identified patterns of the influence of the parameters of the premises with fires are shown as the slit coefficient decreases and the fire load density increases, the actual limit of fire resistance begins to decrease, as well as at values of fire load density less than 600 [MJ/m2], there is an area where the occurrence of a boundary state is not observed and Nomograms for determining the limit of fire resistance for steel structures at standard values of critical temperature were constructed and an appropriate method was developed.

CHARACTERISTIC VALUE OF THE RANDOM FIRE LOAD DENSITY, Probability-based specification depending on the way how the building compartment is used

<p>The algorithm that allows to specify the characteristic value of the random fire load density, depending on the way how the considered building compartment is used, is presented and discussed in detail. The proposed computational procedure is based on a probabilistic approach, the alternative in relation to the traditional methodology according to which the results obtained from the inventory of such a compartment are a basis for the evaluation. It is assumed that the sought value is estimated as the upper quantile of a <em>Gumbel</em> probability distribution which is set at an appropriate level of the probability of its up-crossing. The formal model described in the paper is referred to the two selected and qualitatively different design techniques which are used in practice. The first one is based on the recommendations contained in the Eurocode EN 1991-1-2, whereas the second - on the rules specified in the standard NFPA 557.</p>

Survey of Fire Load in Building Furniture Store

There are many combustible materials in building furniture stores with complex people traffic and high risk of fire disaster. Fire load as the represent of flammable material, and the building fire risk can be grasped by the data obtained. Through investigation and statistics on the fire load density value of building furniture store, it is convenient for performance fire safety design. According to the survey, fire load density average value is determined of 382.71 , the standard deviation is of 143.46 . After fitting the survey data, the data distribution do not refuse to obey the extreme-value Idistribution, so this distribution can be the basis of fire design in other corresponding building furniture stores.