Progressive Collapse 1

[HDR]

My client has made several requests that the structure be designed for progressive collapse. I am familiar with the concept, but am unsure 'exactly' what a successful design should include. Are there any design guides available on this topic?

 

[whymrg]

There are publications:
-"Interim Department of Defense Antiterrorism/Force Protection" standards dated 12/16/99 and
-Army TM 5-853-1 0330 CEMP "Security Engineering Project Development" 12 May 94
-TM 5-853-2 (For Official Use Only) 0309 CEMP "Security Engineering Concept Design" 12 May 94
-TM 5-853-3 (For Official Use Only) 0386 CEMP "Security Engineering Final Design" 12 May 94

You may try to get them contacting

http://www.hnd.usace.army.mil/techinfo/

Good luck.

 

[billyrayjimbob]

Refer to British Standards which include for progressive collapse design.

Main points:
1) Check what would happen if you remove a column. Will structure hang (large deflection acceptable) or will it fail? If it fails, how big an area will fail? If a large portion of structure will collapse upon removal of beam or column then that member should be designed for a special blast load (34kN/m² in UK)
2) Column to beam joints need to be detailed to allow structure to hang in catenary if necessary.

 

[shemp]

mrl,
I researched this topic a few weeks ago for one of my jobs, however the requirement to design to prevent progressive collapse was waived. I did find some useful information in the papers on this website:

http://www.nibs.org/MMC/mmcactiv9.html

As far as a design guide, I don't think there really is one. There are only documents with vague requirements to prevent progressive collapse, such as 'the superstructure should be designed to sustain local damage while limiting the damage to an extent not disproportioate to the original local damage.'

I would venture a guess to say that this topic is probably THE most unregulated topic by the codes in structural engineering that there is. Few people seem to agree on the design methods.

The only systems that I think can work are those with special moment frames or those using the Sideplate connections. But, one of the articles from the website above talked about how even special moment frames don't possess enough continuity to successfully prevent progressive collapse in the 'missing column' scenario. Let us know what type of system you end up using, if you do in fact have to design to this criteria.

Also, one of the articles said that the cost of a project with concrete moment frames designed to prevent progressive collapse increased the building's cost by about 30%. Does your client know this, too?

Is this a government building? in what country?

Shemp

 

[maldoror]

Two goods starting points may be the following:

1) PCI Design Handbook

2) Eurocode 2, Part 1-3

 

[billyrayjimbob]

shemp,

I have to pick you up on your sentence: "I would venture a guess to say that this topic is probably THE most unregulated topic by the codes in structural engineering that there is."

Progressive collapse is well regulated and understood in UK and it never ceases to amaze us that other countries like USA appear to ignore it.

 

[shemp]

billyrayjimbob,
How detailed does the code in the UK get with progressive collapse requirements? The reason I said that it is unregulated by the code is because there is no mention of it in the IBC 2000 (as far as I can tell) and ASCE 7 only mentions it in the commentary. Most of the buildings designed in the US for progressive collapse are Department of Defense facilities or embassies. The DoD's criteria is very vague.

Have you designed any buildings with this type of structure? Must moment connections always be used, or are there different systems to be used? Are many buildings in the UK being designed to prevent progressive collapse? (I guess the fear of another Ronan Point collapse didn't spread over the Atlantic.) Do you know how much the cost for one of these buildings increases?

Thanks for shedding some light on my questions,
Shemp

 

[kieran1]

all buildings over 4 storeys should be designed for progressive collapse. It doesn't increase the costs of framed building as good detailing is usually adequate. It will however increase the costs of load-bearing building significantly

Kieran

 

[shemp]

kieran1,
What type of detailing is adequate to prevent progressive collapse?
Most steel framed buildings have simple connections which would not be adequate for continuity across a missing column. I would think that each connection would have to be a moment connection. Switching to this type of structure would increase the costs, no?
Thanks in advance for your response.
Shemp

 

[ckorski]

Progressive collapse is likely to happen to a structure which is designed conventionally. If you wanted to have a structure to stand this kind of assumption, you have to remove all external collumns before the design phase begins, thereby creating a strong internal collumns as a factor of safety. This is very effective method for wide floor area building. Obviusly the corner collumn (intrnal) is the most stressed member. The collumns size generated in this area after all factors has been considered, must be use for the intermediate columns along the edges of the building. Using a greater factor of safety for the corner colluns(external) will be enough to prevent progressive collapse. Corner column is the most critical member of the whole structure, the stronger this is, the better!.

This is a personal view on the subject.

 

[NigelB]

ACI 318 has several requirements for "Structural Integrity". These requirements are intended to protect against progressive collapse.

Nigel

 

[g0203447]

My field is steel truss. I would suggest due to progressive failure of member by member, peak displacement must be observed as design criterion. It is normal in my field, not sure that can be applied to moment frame.