R8 - SILENTBLOCKS - FRONT AND REAR AXLE FITTINGS Page 20 R8 G
MSc Fire Explosion course work R8
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55 Fire developed at a partially complete 14 level multistory building. A fire grew with temperatures estimated at around 1000°C and although structural steel is estimated to become elastic at around 600°C however, some structural beams were deformed but no structural failure occurred and the integrity of the floor slabs were maintained (constructed using long-span lattice trusses and beams supporting concrete slabs) throughout the fire. The building construction was not completed therefore contained no passive fire-protection on the steelwork. The sprinkler systems & other active measures were not yet commissioned and not in operation. Following the fire, it was observed that no connections had failed. However, there were deformations of bolt holes, broken bolt heads, and some of the connection plates had fractured along the length of their beams but had still managed to transfer shear appropriately, various levels of deformation observed in support structures, those deformations were due to tensile forces induced during cooling. The estimated cost of damage was around £25m Structural analysis following the fire proved that fire protection for structural elements are over specified and are not required as much as once thought, fire-engineering principles can be applied to reduce the cost of fire protection and therefore cost of construction. This became a catalyst for steel companies to carry out research in order to gain an economical benefit which has shown that the inherent fire resistance of this common structural framing system is far greater than is demonstrated using standard fire tests. In the Cardington large scale fire tests it was shown that unprotected beams which would fail within 20 minutes for a simply supported structure using a standard fire test could in fact survive offering over one hour fire resistance. This finding now underpins much of modern structural fire engineering Broadgate, London 1990 Event Statistics Unknown Lessons Learned Duration of fire Number of casualties Cost to industry References None £25 million Broadgate Investigation. 1990.[Online]. [Accessed 31 October 2014]. http://www.mace.manchester.ac.uk Prof.Andwers. Broadgate incident. Fire Explosion Prediction & Investigation, October, 2014, Weetwood Hall Leeds. Type of fire Construction Fire Unknown Ignition Source
Transcript of MSc Fire Explosion course work R8
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Firedevelopedatapartiallycomplete14levelmultistorybuilding.Afiregrewwithtemperaturesestimatedataround1000°Candalthoughstructuralsteelisestimatedtobecomeelasticataround600°Chowever,somestructuralbeamsweredeformedbutnostructuralfailureoccurredandtheintegrityofthefloorslabsweremaintained(constructedusinglong-spanlatticetrussesandbeamssupportingconcreteslabs)throughoutthefire.Thebuildingconstructionwasnotcompletedthereforecontainednopassivefire-protectiononthesteelwork.Thesprinklersystems&otheractivemeasureswerenotyetcommissionedandnotinoperation.Followingthefire,itwasobservedthatnoconnectionshadfailed.However,thereweredeformationsofboltholes,brokenboltheads,andsomeoftheconnectionplateshadfracturedalongthelengthoftheirbeamsbuthadstillmanagedtotransfershearappropriately,variouslevelsofdeformationobservedinsupportstructures,thosedeformations wereduetotensileforcesinducedduringcooling.Theestimatedcostofdamagewasaround£25m
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Structuralanalysisfollowingthefireprovedthatfireprotectionforstructuralelementsareoverspecifiedandarenotrequiredasmuchasoncethought,fire-engineeringprinciplescanbeappliedtoreducethecostoffireprotectionandthereforecostofconstruction.
Thisbecameacatalystforsteelcompaniestocarryoutresearchinordertogainaneconomicalbenefitwhichhasshownthattheinherentfireresistanceofthiscommonstructuralframingsystemisfargreaterthanisdemonstratedusingstandardfiretests.
IntheCardingtonlargescalefiretestsitwasshownthatunprotectedbeamswhichwouldfailwithin20minutesforasimplysupportedstructureusingastandardfiretestcouldinfactsurviveofferingoveronehourfireresistance.Thisfindingnowunderpinsmuchofmodernstructuralfireengineering
Broadgate,London1990
EventStatistics
Unknown
LessonsLearned
Durationoffire
Numberofcasualties
Costtoindustry
References
None
£25million
BroadgateInvestigation.1990.[Online].[Accessed31October2014].http://www.mace.manchester.ac.ukProf.Andwers.Broadgateincident.FireExplosionPrediction&Investigation,October,2014,WeetwoodHallLeeds.
TypeoffireConstructionFire
UnknownIgnitionSource
