va repor

huangyhg

tva report
  should achor plate be used as anchorage  at bottom end of anchor bolt.
tva made research on this subject in the early 80s. i would like to recieve information on this subject

no, a heavy hex nut is the optimum for headed anchor bolts/rods.  plates bend unless very thick.  i have used an embedded 3/4" thick ring to hold 22 anchor rods in correct relative position to each other but the pull out value used came from the nut on the end of each rod. see aci 318-05 appendix d.
i agree with civilperson.
some advocate checking the "bearing" of the plate against the concrete but i don't agree with this. the flexibility of the plate with cause bearing directly against the nut.
thanks for replying for my query. i am new structural engineer and i found plates were provided in the drawing ,which i was reviewing.my project manager told me it is wrong. i am trying to understand why some structural engineers are using it.
this a left over habit or detail that needs to be fixed, like hooked anchors or submerged keyways in footings for walls.  both items are contraindicated.