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Showing posts with label structural fire testing. Show all posts
Showing posts with label structural fire testing. Show all posts

Sunday, January 18, 2015

Tisova Fire Tests - Week 1



The setting for the Tisova fire tests could not be more picturesque, cool crisp winter days near a river in the western province of Carlsbad, on an old coal processing site. Over the past week you would have found a small band of academics making holes in floors, ceilings, walls, and beams in one of the buildings located on this site 25 minutes to the west of Karlovy Vary (where we are staying).  Whilst this is a lot of fun, it is all in the name of research.  

Karlovy Vary at night from our apartment

The aim:

To understand the structural effects of a travelling fire on concrete and composite structures, both during the fire and residually after the fire has cooled back to ambient. We are aiming to run the test on the 28th of January.  

Who’s involved:

University of Edinburgh, Technical Research Institute of Sweden (SP), Imperial College London, CSTB, Lulea Technical University, Czech Technical University in Ostrava, MajaCzech, and the Fire and Rescue service of the Karlovy Vary region. 

When did we start:

Set-up on site started on the 13th of January with two members from SP (David Lange and Fredrik Kahl) marking out holes for instrumentation and setting up the lighting for working into the evenings.  Jamie Maclean and I (David Rush) arrived on site on the 14th of January having set-off from Edinburgh on the 12th with a van full of equipment.

The test building

What have we done so far: 

The first week has been mainly drilling holes through the concrete and composite slabs for the 60 plate thermometers, drilling into the concrete and composite slab at various depths to place 112  thermocouples, and installing the 56 thermocouple trees in the fire compartment.  On top of this we have taken out the internal steel partitions that were in the fire compartment, made many holes in the plasterboard partitions on the floor above the fire compartment to run cables to the data loggers, broken a sledge hammer trying to break through a bathroom floor and created a lot of additional dust.

Thermocouple trees inside fire compartment (Photo credit Dave Lange)

Trials and tribulations:

Jamie Maclean and drill
So far there have been few trials to speak of, the only two of note are locating the troughs in the composite slab so that we can accurately measure temperatures, and a delay in the wood supply due to the time that its taking to dry it.

What’s next:

Over the next week the numbers on site will swell to around 10, meaning that we can start hooking up the 700 or so measurement channels, placing the wood (when it arrives), protecting  the necessary cabling in the fire compartment, and install the remaining thermocouples and deflection gauges

Highlights:

Globus is a big positive for us with tasty sandwiches, coffees, and pastries that keep us full of energy for the long days on site.  Finding drill bits long enough to drill 650mm into a concrete beam from above, which we wouldn’t have found had it not been for the very helpful and patient English speaking lady at the local hardware store, which we have visited everyday so far with random lists of equipment that we need.

(Photos copyright of David Rush)

Saturday, June 21, 2014

A couple of recently published journal articles


Some recent research from Edinburgh staff and students have found their way into academic journals.

Title: An application of the PEER performance based earthquake engineering framework to structures in fire

Journal: Engineering Structures [01/2014; Vol. 66: pgs100–115].
DOI: http://dx.doi.org/10.1016/j.engstruct.2014.01.052 

Authors: David Lange (SP, Sweden), Shaun Devaney, Asif Usmani (both University of Edinburgh)
Keywords: Structures in fire; Performance based design; PEER; Fire engineering; Probabilistic analysis.

Abstract:  The Pacific Earthquake Engineering Research (PEER) Center’s Performance Based Earthquake Engineering (PBEE) framework is well documented. The framework is a linear methodology which is based upon obtaining in turn output from each of the following analyses: hazard analysis; structural analysis; loss analysis, and finally decision making based on variables of interest, such as downtime or cost to repair.
                 The strength of the framework is in its linearity, its clear flexibility and in the consideration of uncertainty at every stage of the analysis. The framework has potential applications to other forms of extreme loading; however in order for this to be achieved the ‘mapping’ of the framework to the analysis of structures for other loading situations must be successful.
                 This paper illustrates one such ‘mapping’ of the framework for Performance Based Fire Engineering (PBFE) of structures. Using a combination of simple analytical techniques and codified methods as well as random sampling techniques to develop a range of response records, the PEER framework is followed to illustrate its application to structural fire engineering. The end result is a successful application of the earthquake framework to fire which highlights both the assumptions which are inherent in the performance based design framework as well as subjects of future research which will allow more confidence in the design of structures for fire using performance based techniques.
                 This article describes the PEER framework applied to structural earthquake design then follows the framework from start to completion applying suitable alternative tools to perform each stage of the analysis for structures in fire.


Title: Design of intumescent fire protection for concrete filled structural hollow sections

Journal: Fire Safety Journal [Vol.67; (2014); pgs 13–23]
DOI: http://dx.doi.org/10.1016/j.firesaf.2014.05.004

Authors: David Rush, Luke Bisby (both Univeristy of Edinburgh) Martin Gillie (University of Manchester), Allan Jowsey (International Paint Ltd.), Barbara Lane (Arup)
Keywords: Composite columns; Intumescent fire protection; Forensic analysis; Section factor; Limiting temperature; Design.


Abstract:  Design of intumescent protection systems for concrete filled structural steel hollow (CFS) sections in the UK typically requires three input parameters in practice: (1) a required fire resistance rating; (2) and ‘effective’ section factor; and (3) a limiting steel temperature for the hollow structural section.  While the first of these inputs is generally prescribed in building codes, the latter two require greater engineering knowledge and judgement.  This paper examines results from standard furnace tests on 26 CFS sections, 14 of which were protected with intumescent coatings by application of current UK design guidance. The protected sections demonstrate highly conservative fire protection under standard fire exposure, a conservatism not typically observed for protected unfilled steel hollow sections. The possible causes of the observed conservatism are discussed, and it is demonstrated that the method currently used to calculate the effective section factor for protected CFS columns is based on a false presumption that both unprotected and protected CFS columns can be treated in the same manner. A conservative method for determination of the steel limiting temperature for CFS columns is proposed; this can be applied by designers to more efficiently specify intumescent fire protection for CFS members.