Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

glulam failure

[Subject Prev][Subject Next][Thread Prev][Thread Next]

While we are debating the viability of this forum, how about a quick engineering question? J 


There is a 150,000 sq. ft panelized roof constructed in 1980 with multiple glulams in various states of failure, all the way from “looks fine” to “lets shore that one right now”.  Due to the large spans (60’ and 48.5’) and accessibility, I am going to recommend that we use post tension techniques to fix the failed one(s) vs steel sections.  They exhibit classic bending failures…some lams are separated by 1 ½ and the cracks propogate cross lamination in a shallow “v” from the mid span.  I don’t know of any other technique that would be very viable for an option. 


I am going to conduct a thorough observation of all the beams tomorrow and my question is:  Given that all of the glue is suspect due to two failures already and the time period it was constructed in, do any of you have any guidance on criteria or general comments on how to determine how much delamination is “ok”?  What is the best metric to use? Would you measure current deflections of all of the beams? 


Has anyone had experience using FRP for wood beam repair?  How did it go?  Cost effective?  The reps say it’s great….  Since the wood is in great condition, I think it would be a possibility but I would have to get additional guidance on that.


Other info: based on my initial site visit, moisture has not played a role.  Based on my initial calcs, the beams are in the 95-98% of allowable bending stress range.