Has a Contractor requested an alternate method for leveling steel columns from what is indicated on your column design details?
SE University is compiling examples of Common Requests for Information (RFIs) sent to the Structural Engineer of Record during construction. 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.
RFI #3: Alternate Method For Leveling Steel Columns Requested.
Example: Contractor requests the use of heavy hex setting nuts in lieu of leveling/setting plates shown in structural details.
Resource Information:
- Generally, this RFI falls under Contractor means and methods for erecting and leveling steel columns. However, there are guidelines in AISC Design Guide 1, Section 2.9 to determine if the requested method is appropriate for your condition. For example, the setting nut method is recommended only for columns lightly loaded during erection.
- An additional point to consider is if the grout bed thickness specified is appropriate for the Contractor’s preferred setting method. If a heavy hex nut is used between the bottom of base plate and top of concrete foundation, check that the height of the hex nut for the specified anchor bolt diameter is equal to or less than the grout bed thickness. Refer to AISC RCSC Specification Table C-2.1 for heavy hex nut heights. Otherwise, an alternate use of leveling will be needed or the grout bed thickness will need to increase. There could be complications in increasing grout thickness if the columns have been fabricated.
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.