rowingengineer
Structural
- Jun 18, 2009
- 2,466
In the New Zealand code it has this requirements for fire walls,
2.2.4 AS/NZS 1170 Part 0, Clause 4.2.4
Replace the Clause with the following:
“The combination of actions for checking
strength and stability for the ultimate limit
state for fire shall be as follows:
(a) During the fire:
(i) [G, thermal actions arising from fire,
ψl Q ]
together with:
(ii) a lateral force of 2.5% of (G + ψCQ)
applied as per Clause 6.2.2.
(b) After the fire until the building is either
repaired or demolished:
(i) [G, thermal actions arising from
fire, ψl Q ]
together with the more critical of either:
(ii) a lateral force of 2.5% of (G + ψCQ)
applied as per Clause 6.2.2.
or
(iii) a uniformly distributed horizontal face
load of 0.5 kPa in any direction.
Account shall be taken of the effects of the
fire on material properties and the geometry of
the structure.”
This implies that all fire walls should be designed for 0.5kpa lateral loading however gives very little advice on the supporting structure requirements.
Ie we have a steel building with fire walls, if the roof gets to hot and collapses do we need to cantilever up the walls and ignore the frame in the analysis? This is the interpretation I have been adopting, but am interested to know if there are any other interpretations.
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."
2.2.4 AS/NZS 1170 Part 0, Clause 4.2.4
Replace the Clause with the following:
“The combination of actions for checking
strength and stability for the ultimate limit
state for fire shall be as follows:
(a) During the fire:
(i) [G, thermal actions arising from fire,
ψl Q ]
together with:
(ii) a lateral force of 2.5% of (G + ψCQ)
applied as per Clause 6.2.2.
(b) After the fire until the building is either
repaired or demolished:
(i) [G, thermal actions arising from
fire, ψl Q ]
together with the more critical of either:
(ii) a lateral force of 2.5% of (G + ψCQ)
applied as per Clause 6.2.2.
or
(iii) a uniformly distributed horizontal face
load of 0.5 kPa in any direction.
Account shall be taken of the effects of the
fire on material properties and the geometry of
the structure.”
This implies that all fire walls should be designed for 0.5kpa lateral loading however gives very little advice on the supporting structure requirements.
Ie we have a steel building with fire walls, if the roof gets to hot and collapses do we need to cantilever up the walls and ignore the frame in the analysis? This is the interpretation I have been adopting, but am interested to know if there are any other interpretations.
"Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning."