THE INFLUENCE OF DAMAGE TO PASSIVE FIRE PROTECTION SYSTEMS CAUSED BY EARTHQUAKES AND DEFECTS IN GENERAL

摘要

Passive fire protection (PFP) systems that are damaged by earthquakes may suffer significantrnreductions in fire resistance, resulting in increased risks to life safety in the event of an outbreak ofrnpost-earthquake fire and subsequent spread. In the aftermath of the Canterbury (New Zealand)rnearthquake events, damage to PFP systems has been surveyed in moderately damaged buildings. Therndegree of damage observed ranged from minimal, to moderate damage where some fire resistancernremains, to extensively damaged where no protection remains.rnThis paper focuses on damage in the moderate range where the majority of PFP systems protecting arnfire compartment were largely intact, but one or two systems such as a doorset or a firewall werernshowing some degree of damage that compromises the protection of the whole fire compartment.rnFollowing the building surveys, selected elements of damage to PFP systems were built into the firernresistance test specimens as defects and instrumented with thermocouples to assess the failurernmechanisms. The reduction in fire resistance of the damaged systems was correlated to the degree ofrndamage such as size of gaps, furnace pressure and oxygen content of the fire gases and then comparedrnwith fluid flow theory in restrictive openings.rnTraditionally, the focus has been on the risk of fires immediately following an earthquake event whenrnthe occupants are evacuating, and damaged PFP coupled with inoperable sprinklers due to loss ofrnwater supply and impeded egress routes are likely to impact life safety. It is now also acknowledgedrnthat PFP may be damaged in an otherwise structurally safe building that may be reoccupied postearthquake;rnthis research also provides a basis for building assessors to require that damaged PFP bernrestored to specification.