SEU, a program provided by SE Solutions, LLC

Common RFI #1: Holes Between Two Connecting Steel Elements are Misaligned

Have you even been asked to provide a field fix for misaligned bolt holes in a steel structure? Is this an example of a common RFI you have received?

SE University is compiling examples of Common Requests for Information (RFIs) sent to the Structural Engineer of Record. Following each RFI, we provide some resource information based on experience from contributing structural engineers. We hope you will find this resource information useful as you customize it to meet your specific project needs. Tips to avoid the RFI during the design phase may also be offered.

The Common RFI presented in this post is for Steel Projects.

1. RFI: Holes between two connecting steel elements are misaligned.

Example: Where a steel post bears on a steel beam, the steel post base plate holes provided by a miscellaneous metal subcontractor do not align with supporting steel beam flange holes as fabricated.

Resource Information:

  • If the holes are slightly misaligned, ream one hole to align with the other hole. Larger washer plates can be welded to the reamed hole with the correct bolt hole size in the washer plate to ensure that the bolt does not move greater than originally intended. Provide maximum reamed hole size, minimum spacing to adjacent holes, and minimum edge distances to maintain for reamed hole. See AISC Engineering FAQ 2.5.5 for additional information on reaming.
  • Another option is to abandon one hole and drill a new hole to align with the connecting element, as long as the remaining effective net section is adequate for the anticipated loads. Ensure minimum bolt spacing to abandoned hole and minimum edge distance is maintained per AISC Specification. The abandoned hole can be filled with weld metal if water seepage is a concern. See AISC Engineering FAQ 2.5.3 for additional information.
  •  Alternately, fabricate a new connecting element with corrected bolt hole locations and sizes.

 

We hope this will be a helpful resource to reference best practices within the SE community. If you would like to share an RFI and reference information you have used, please add a comment below or send an email to Cathleen Jacinto.