PSI - Issue 72

Ivan Aranđelović et al. / Procedia Structural Integrity 72 (2025) 354 –361

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Table 4. Fire resistance of the building structure for boiler room in which liquid fuels are used Q m [ МЈ/ m2] 0÷251 252÷502 503÷1004 1005÷2009 Р0 1.0 1.2 1.4 1.6 W 1.0 1.3 1.5 1.6 FR [min] < 30 30 60 90

4. Analysis - Gretener’s method - version TRVB 100:2010 Based on the research of the Swiss engineer Gretener, two methods for fire risk assessment were standardized:  The Swiss Society of Engineers and Architects (SIA) published SIA81 method in 1981 and SIA2007 in 2007;  The Austrian Fire Brigade Association published TRVB 100 Technical Recommendation in three versions issued in 1975, 1987 and 2010. The decision on the necessary fire protection measures is made on the basis of the calculated value of the factor of preventive fire protection measures ( S G · F G ) and the estimated value of the fire resistance of the building structure ( F G ). The following equation is used to determine the S G · F G factor:   4.42 6.25 G G G G B S F    (9)

In this case factor G is calculated according to the equation:

5 10 A b 

(10)

G



where A is area of the fire sector [m 2 ] and b is width of the fire sector [m]. In this case the most unfavourable scenario is assumed: A = 3,000 m 2 and b = 40 m when G = 1.2 it follows that 0.90 G G G S F B    (11)

where B G is specific fire hazard factor calculated from the equation:

(12)

G G G G G G G G G B Q C R K A P E H        

where E G is fire brigade intervention factor, A G is the factor of fire activation, P G is people harm factor, Q G is specific fire load factor, C G is factor of combustibility, R G is smoke hazard factor, K G is corrosion hazard factor and H G is building height factor. Based on the assumptions and recommendations from TRVB 100:2010, in this case Q G = C G = R G = K G = P G = A G = 1. Factor H G = 1 because the boiler room is located on the ground floor and E G = 0.83 because the nearest professional fire brigade is 5 km away. Therefore, in this case specific fire hazard factor can be calculated as: 1111110.831 0.83 G B          (13)

It follows that:

0.90 0.83 0.75 G G S F    

(14)