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Acceptable failure rate for glass

Acceptable failure rate for glass

Acceptable failure rate for glass

Does anyone know if there any codes that gives clear guidance on this?

in Canada I use CGSB 12.20-M89 and ASTM E1300, for application of windows the typical acceptable probability of failure is 8 in 1000 once design load exceeds capacity, both codes give vague indication in the commentary that this is intended for window, and if the consequence of failure is more severe, the acceptable prob.fail should be adjusted. GANA glazing manual says it is common to use 1 in 1000 for more critical structural elements. My questions is are there code prescription/requirement on probability of failure for different application, or is this is a judgement call on the engineer of record?

For example, if I design a glass floor with failure rate that is same as those of window, but I have calculated a reasonable post-breakage design resistance (e.g. can resist 50% service load once glass breaks), then I would argue the post-breakage failure is not serious, therefore the 8 in 1000 probability is appropriate. Can anyone weigh in on this with their knowledge

RE: Acceptable failure rate for glass

See ASTM 2751-17 Standard Practice for Design and Performance of Supported Laminated Glass Walkways. I doubt people will use a glass walkway that has a high probability of cracking even if there is no danger of collapse.

RE: Acceptable failure rate for glass

When designing structural glass elements that must account for post-breakage life safety, I always design to allow for %100 resistance of load post breakage.

ex: glass floor - I assume you will have a laminated unit - either side of the laminated sheet must be able to withstand full loading, with either side broken.

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