1 August 1998
construction. Masonry walls are particularly susceptible to damage if not properly integrated
into the design. They may be supported, or isolated, but it is important to insure that
movement of the building structure does not overstress the masonry. Similarly, when separate
support columns are used for top running cranes, they must be supported so that differential
movement between the crane columns and building columns, due to differences in stiffness,
does not overstress either column and result in local column buckling. Drift limitations are an
area of contention among structural engineers and significant engineering judgment is required
when limitations are established. Application of a requirement that is too stringent can
significantly impact the cost of a structure. Requirements that are too lax can lead to damage
of rigidly connected components. This is an area of special interest for the Independent
e. Design Analysis. A complete building design analysis consists of at least 2 parts, the
building design and the foundation design. Computer designs are prevalent in the industry
and may be difficult to review and CEGS 13120 includes provisions designed to assist in this
regard. Since all computer design analyses are certified by a licensed Professional Engineer,
it is generally sufficient for the project structural engineer to limit his/her review to the
input/output portion of the analysis. Verify that the specified loadings have been properly
applied, the wind loads have been properly calculated, and that the output results are properly
reflected on the shop drawings. Hand calculations to verify the assumptions and the method
of analysis for arriving at the final results should only be requested in unusual cases.
Foundation design analyses should be reviewed following established Architect-Engineer
f. Submittals. Design analyses and erection procedures should be reviewed by
Engineering as an extension of design.
g. Erection Plan. Obtaining an acceptable site-specific erection plan is sometimes difficult.
The building manufacturer frequently requires the erector or another third party provide the
plan. Caution should be exercised when long span structures or other structures requiring
unique design solutions are procured. Separately contracted erectors may not appreciate the
need for additional bracing during construction and problems could result. Several Corps
structures have collapsed during construction due to inadequate bracing/erection plans. The
requirement for a site specific erection plan should be strictly enforced with the contractor. A
review by the building manufacturer may be warranted when plans are prepared by a separate
erector for a complicated structure.
h. Warranties. Specified warranties obtained from the Metal Building System
manufacturer only apply to manufacturer supplied items. If masonry walls are used in lieu of
metal siding, any problems with the walls are covered under the general contractor's warranty,
not under the Metal Building System warranty.
i. Welding. If CEGS 13120 is used for large hanger type buildings or where more critical
welding is involved, the manufacturer must have proper quality control of shop welds. If the
metal building manufacturer is not AISC MB certified, then a separate specification on welding
requirements should be added to the contract (CEGS 05055, Welding, Structural).