Dhaka factory collapse

April 26, 2013 § 4 Comments

Sorry to bring the house down, but having just sat in on our ‘rookie’ structures prof (sorry, Chuck..!) delivering an introductory concrete lecture to our first year grad students, the collapse of a reinforced concrete frame structure in Dhaka early this week was especially sobering.

Chuck made the point that reinforced concrete has to be designed so that the steel reinforcing fails first, since it will fail slowly, in tension.  If the reinforcing is too strong, the concrete itself will crush in compression, which is a more violent and sudden occurrence.  Reinforcement failures give you time to notice that the structure is sagging and cracking, which in theory gives you time to evacuate the structure.

And, from news reports, that’s exactly what happened.  The Rana Plaza apparently began failing a full 24 hours before its collapse, and there are reports that workers notified various factory managers of cracks in walls and girders.  Unbelievably, several of the factories housed in the structure opened for business the next day despite these cracks, apparently forcing workers to go back into the building.

The Times this morning suggests that these managers were acting under tremendous financial pressure to continue business as usual, and there are obvious parallels here with the fire in a Dhaka factory last November in which workers died in part because they were locked in to dangerous workshop rooms.  In both cases, clothing in the wreckage has revealed that firms ranging from Tommy Hilfiger, the Gap, and Children’s Place may have been among the brands whose price points these managers were trying to meet.

It’s unconscionable that, given everything we know about structural and life safety design, these disasters can happen in some parts of the world and not others.  Being born in Dhaka shouldn’t mean that your surroundings are any less well-designed or engineered, or monitored, than anywhere else in the world.  It’s hard to imagine engineers and architects tossing out their standard-issue Gap button-downs, and I’m as guilty as anyone of taking advantage of off-the-rack brands’ affordability, but given what our professions know about failures like these, we surely owe the world a better situation than these workers faced…

Advertisements

§ 4 Responses to Dhaka factory collapse

  • Jason says:

    So given the events that led to the Dhaka collapse, what did the engineers/architects do wrong that could have been avoided? I know the product demand portion lies on our consumerism, but what do you feel the design teams could have done? Sounds like people recognized the failure prior but “chose” to ignore them. To me and this may seem harsh but it sounds like a case of the Stupids. And there is a long standing saying that tells us that can’t be fixed.

    But what caused the failure in the first place? Overloading by owners, Undersizing structures, poor materials/placement/ or handling by the contractor? Those are things that the raised my eye to this. Lets be honest, all buildings fail! It is just a mater of time and how. In the US we demo many buildings before nature does. So like you said our job is to do so in a way that it is not an instant collapse but gives as much time to escape as possible.

    Now how do educate the world as to how to identify that failure as a sign of an emergence? No idea since many of those folks have never recieved any formal education in the first place. Hopefully the people that knowingly forced others to remain in the building get their fair justice.

    • twleslie says:

      Good points. I don’t think the engineers or architects (if there were any…) were at fault here. From more recent news reports, it sounds like the building had several floors added to it, apparently a common practice in Dhaka. And it also seems likely that the floors themselves were loaded well past whatever they were designed for–if, in fact, they were professionally designed at all. My point was that the managers forced hundreds of workers into a structure that was broadcasting its own imminent failure–an unconscionable thing to do. But those managers were responding to pressure from western companies, who must surely bear some responsibility for contracting with them. And, if you follow that chain all the way, you arrive at the uncomfortable but hardly debatable proposition that this is the price paid for cheap garments in the western world.

  • Don F says:

    At the risk of proving why internet diagnoses are useless, the pictures of the rubble seem to show too-light reinforcing. Reinforced concrete is popular in the developing world because it’s inexpensive; rebar is often skimped on because it’s the most expensive part. Every engineer I know (including, you know, me) was horrified by the obvious contribution of under-reinforcing to the extent of damage in the Port au Prince earthquake. The same problem looks like it may exist here, even though the immediate cause of the collapse seems to be overload from unplanned additions, as you say.

    • twleslie says:

      It’s one of those building failures that has multiple ’causes,’ I guess, any one of which (overbuilding, overloading, under-reinforcing, proper maintenance/attention to cracking, evacuation) would have kept this off the news entirely…

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

What’s this?

You are currently reading Dhaka factory collapse at architecturefarm.

meta