I am working on a project where we are replacing a base plate with anchor bolts. The location of the base plate is slightly offset from the original location, so we are planning on cutting the original anchor bolts flush at the top of slab.
From my previous experience, I thought that if you simply cut an installed anchor bolt at the top of the slab, in anchor bolt analysis, you would have to consider this anchor bolt as an edge distance/installed anchor in the evaluation of the new anchors. Based on this assumption, the only way to not consider the anchor bolt as an edge distance is to remove the existing embedment of the anchor and completely fill the hole with grout.
Please let me know if this assumption is correct or if cutting the original anchor bolt, flush with the top of the slab, would allow the anchor bolt to not be considered as an edge in the evaluation of the new anchors.
Michelle,
Hilti does not have any test information regarding the effects of abandoned anchor bolts near a newly installed anchor; however, attached is a copy of the University of Tennessee Abandoned Hole reference study for your reference. Although this study is mainly focused on expansion anchors, many designers have used this an a general overall appraoch for all mechanical and adehsive anchors.
An alternative approach would be to treat the cut-off/abandoned anchor as an edge distance, and install the new anchors based on that distance. Ultimately though, it will be up to the design engineer on the project to verify which approach would be most applicable.
Let us know if you have any additional questions.
Regards,
Bryan
Michelle,
Since Hilti has not performed any testing for abandoned/cut-off anchor bolts, there is no data that can be referenced for your scenario. As seen from the research study, it can be seen that empty holes seem to have more of an effect as compared to cutoff bolts. In the end, since the design engineer on the project will have to use their engineering judgement, it is also common that onsite evaluation is prescribed to verify its anchor capacity.
Let us know if you have any additional questions.
Regards,
Bryan