Buildings Requiring Blast Resistant Design

For low-hazard situations, blast-resistant design is not required because a fire is more likely than an explosion in case of a flammable vapor release. Where little or no explosion hazard (low hazard) exists, it is only necessary to meet conventional building code requirements, including those for fire protection. 

Several important concepts should be kept in mind while designing buildings for blast resistance. These concepts include energy absorption, safety factors, limit states, load combinations, resistance functions, structural performance considerations, and most importantly, redundancy. A design satisfying all required strength and performance criteria would be unsatisfactory without redundancy. 

Most details for this type of construction are not uniquely influenced by blast resistant design. For steel frame buildings, appropriate AISC steel details used for plastic design methods should be used. The attachment of the siding and roofing requires special attention and the details shown in Figure 8.1 are applicable. 

The building s doors, due to their functional requirements and associated hardware limitations, arc a weak link in blast resistant design. Since doors are likely to be the largest opening into a building they provide the largest potential source of... 

The control room discussed in Example 2 is located 150 ft (45 m) from the nearest process equipment in the unit. Since the building occupancy exceeds the company criteria, further evaluation is required. The building was designed to be blast resistant to 5 psi (0.34 bar). 

As Figure 6.2 shows, Building 2 is potentially subject to 3 psi (0.2 bar) from Process Unit 2 and 1 psi (0.07 bar) from Process Unit 1. Since Building 2 is not designed for blast resistance, as indicated by Table 3.5, occupants could be subjected to possible injury or fatality. Therefore, Building 2 requires further evaluation. 

For biast resistant design of buildings, the principal parameters of the blast wave required to define the blast loading for a building s components are ... 

This chapter addresses blast resistant considerations for doors, windows, utility openings, and special exterior and interior requirements. These considerations should be jointly addressed by the building design team. 

Connections for precast panels can be a problem for blast loaded buildings. Typical connections for walls rely on direct bearing for support of the panel for positive loads, and weld plates for negative loads such as wind suction. Rebound of stiff panels due to blast toad can be very high, and the connections typically used in conventional design may be inadequate to resist this load. Substantial and expensive changes arc often required to develop the full capacity of precast panels. 

---