huangyhg

gov. says big dig tunnel bolts unreliable
this is the latest news about the big dig epoxy anchors:
i don’t think it says in the article, but i’m assuming these tests referenced by the mass gov. were done after the collapse. what a shame this wasn’t discovered during construction.
i will think twice about specifying epoxy anchors in direct tension situations until i hear the cause of these problems. sorry hilti.
most of these anchors are governed by a safety factor of 4, and some use 8 without special inspection. they still fell! that's pretty bad. there's something to be said for properly cleaning those holes. i wonder what the actual cause was.
i spoke with a hilti rep today and asked him if hilti was involved in any way. he said that they are investigating but i got the impression that it wasn't their bolts. he indicated that the little red cone on the bolt was not something he'd seen before and was doing a web search to find out who's it was.
he stated that at some point hilti was going to issue some sort of statement.

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