» Read more recent posts about base plates and the latest version of ANSI MH16.1.

When replacing or repairing a damaged rack column, it’s important to also assess its base plate (sometimes called foot plates). Base plates at the bottom of every rack upright connect the anchor bolts between the column and concrete slab. Drilling anchor bolts into the floor through the base plates significantly reduces the risk of the industrial steel storage rack sliding or falling over if impacted.

RMI Standard Requires Anchoring of Base Plates

In addition, Section 1.4.7 of the RMI ANSI MH16.1: Specification for the Design, Testing and Utilization of Industrial Steel Storage Racks requires column anchors. In the case of a column damaged by an impact, the base plate may separate from the column or the floor. Or, it may show signs of deformation. Based on an evaluation, a qualified storage rack design engineer may determine the need for a new base plate. Additionally, the previous hole locations could no longer be accessible or usable.

Because the bending stiffness of the base joint may be critical the column repair’s success, RMI recommends several best practices. Section 8.3.2 of the recently updated Guideline for the Assessment and Repair or Replacement of Damaged Rack — Version 2.0 notes:

The column base plate needs to be shown to meet the loading requirements of the applicable loading combinations in ANSI MH16.1: Specification for the Design, Testing and Utilization of Industrial Steel Storage Racks, Section 2.1 or Section 2.2. The base connection shall be evaluated for the following factors including, but not limited to:

Should the replacement anchors for the new base plate need a different placement location than before, the supervising engineer determines an alternative solution. Per the Guideline’s Section 9.4: “The supervising engineer should consider the location of existing anchor holes and should design the kit for repair or replacement for proper anchoring. It is not acceptable to leave repaired rack unanchored.”

Replacement Anchor Bolts and Base Plates

In certain cases, longer anchor bolts can secure the base plate to the floor via the existing holes. Alternately, in other situations, filling the existing holes enhances the integrity of the floor surrounding the new anchor bolts. The Guideline details the following best practices for replacement anchors in section 8.3.2:

If replacement anchors cannot be reinstalled in the same place relative to the column, a new location would need to be designed and evaluated. Replacement anchors shall be installed in the same hole or a new hole not less than 3 times the larger anchor diameter from existing anchor holes, whether the holes are empty or contain the remnants of old anchors. If existing anchor holes are filled with “dry-pack mortar” and the mortar has set for at least 7 days, replacement anchors may be placed not less than 1.5 times the diameter of the largest anchor from existing holes.

Following these guidelines when securing a column’s base plate to the floor ensures the structure remains stable and upright. This significantly reduces the risk of a collapse. It also improves the safety of personnel working in the area.

Learn More About Rack Repair

Looking for more information about rack repair best practices? Download RMI’s Guideline for the Assessment and Repair or Replacement of Damaged Rack — Volume 2.