http://cee.uiuc.edu/kuchma/strut_and_tie/
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See Section 17.8, Openings in Beams, ""Reinforced Concrete Fundamentals, 5th Ed", Ferguson, Breen, and Jirsa, Wiley, 1988. ISBN 0-471-80378-2.Bill Scott
From: alfred mueller [mailto:alfred.mueller@hmb-ingenieure.de]
Sent: Saturday, December 08, 2007 12:01 AM
To: seaint@seaint.org
Subject: AW: Openings in concrete beamsHi David,
as the other two colleagues said, there is no problem to design RC- beams with openings. I have designed some of these in recent projects. I know several books, where are some explanations about that, but they are all in german speech. I don't know, if some of them are translated. But there are also some explanations in the german code and therefore also in the European code, I think. So you should get this in english speech.
If you want, maybe, I can scan some papers out of my books and send them to you.
Regards
AL
Alfred Mueller, SE, IWE
hmb- engineers, Karlsruhe, Germany
University of applied sciences, Karlsruhe, Germany
Von: Gaines, David [mailto:David.Gaines@hdrinc.com]
Gesendet: Freitag, 7. Dezember 2007 20:57
An: seaint@seaint.org
Betreff: Openings in concrete beams
Has anyone seen this in practice or done concrete beam design with openings before?
We are working on a new underground concrete parking structure with limited height and overhead clearance restrictions. The footprint is large, like 600 feet in the short direction so we need ventilation. We have 32 foot long and 63 foot long beams and 32 foot long girders. The longer beams are governed by bending, not shear at mid-span. I have preliminary beams designed to just fit the height. The architect is asking us if we can put an elongated hole in the beams and girders for ducting and pipes. These of course would be at the mid-span and not exceeding 1/3 the depth. I would prefer to use a round hole but they are asking for elongated holes. I can't find anything in text books or literature for designing an opening in concrete beams.
Has anyone done this type of beam design method before? Has anyone seen concrete structures designed with openings in the beams? Does anyone have a book or reference I can look for to find examples or methodology?
Seems like it would be more efficient to increase the floor to floor height and run the ducting underneath. Any comments on this?
Any help or input would be appreciated. Thanks,
Dave Gaines
Dave Gaines, P.E.
Structural Project Engineer
HDR ONE COMPANY | Many Solutions
251 S. Lake Ave, Suite 1000
Pasadena, CA 91101
T: 626.584.4960
F: 626.584.1750
email: david.gaines@hdrinc.com