C-A4A4 Structural design documents and specifications

A4.1 Structural Design Documents and Specifications Issued for Construction

This Specification provides minimum requirements that are deemed effective to provide satisfactory results in steel buildings and other structures within the intended

scope of the Specification. It is not intended or necessary to list all the requirements stated in the Specification for listing in the design documents and specifications issued for construction. The items specified in this section are deemed to be important for specific mention and to be listed. When modified or additional requirements are warranted for a particular project, these should be considered by the designer and direct references to the Specification should be employed where appropriate.

The information specified to be shown on design documents issued for construction is considered important for ensuring that all applicable elements of the structural steel frame, including connections, are documented and addressed by the engineer of record (EOR) as required by the Specification. The 2021 International Building Code (IBC) (ICC, 2021) requires that a registered design professional in responsible charge be assigned the role of reviewing and coordinating submittal documents prepared by others, including phased and deferred submittals as defined in Chapter 1 of the IBC. Some design information required for final construction as listed in Section A4 may be contained in deferred submittals prepared by a specialty structural engineer, if approved by the authority having jurisdiction. This practice may be used for metal buildings and for joists and joist girders. The authority having jurisdiction (AHJ) is the final authority dictating requirements for design documents issued for permit and for final construction. Refer to the 2021 IBC and CASE Document 962-B (CASE, 1996) for further information.

For projects that use a design-build delivery method, where the EOR or internal design engineer, as applicable, is employed by the fabricator or incorporate deferred submittals, such as buckling-restrained braces, custom fabricated trusses, or steel connections, some information specified in Section A4 is transmitted between the designer and fabricator internally and there may be no need to issue documents from one entity to the other in order for construction to commence. However, the intent of Section A4 is to document the information between parties. Section A4 anticipates that this documentation would be in the form of structural design documents and specifications as specified, although it is recognized that other means of documenting the required information are possible.

When the AHJ, applicable building code, purchaser, owner, or EOR judge that supplemental life safety requirements are advisable, such requirements should be indicated in the documents that are released for construction. Such requirements might include, for example, material testing, reporting and traceability, additional quality control and nondestructive testing, specific erection requirements, or other important items critical to life safety.

In reference to item (k), preset elevation requirements at free ends of cantilevered members relative to their fixed-end elevations, it may be necessary to specify a relative elevation to which the free end of a cantilever must be erected (preset) prior to load application, with the fixed end stabilized before the member is released from the crane or temporary support and any other load is applied to it. This is needed so that the cantilevered member can be detailed and fabricated to allow for any required preset. This does not apply to a beam that is continuous over a support, which is controlled by camber, not preset.

Design of Structural Steel Connections. It is recognized that various means of designating and designing structural steel connections have been used in structural steel construction. Therefore, it is important to address these means in this Commentary. The Code of Standard Practice (AISC, 2022a) describes three options that can be used. One of these options should be indicated for each connection in a project. It is acceptable to group connection types and utilize a combination of these options for the various connection types involved in a project.

When the EOR intends to provide complete connection design in the structural design documents (described as Option 1 in the Code of Standard Practice), the design drawings should include the following:

• (a) All weld types, sizes, lengths, and electrode specification tensile strengths
• (b) All bolt sizes, locations, quantities, and grades
• (c) All plate and angle sizes, thicknesses, dimensions, and grades
• (d) All work point locations and related information

Welds should be specified as required by AWS D1.1/D1.1M (AWS, 2020). This includes the following:

• (1) The effective weld length and required effective throat for partial-joint-penetra- tion groove welds.
• (2) The effective weld length and leg size for fillet welds.
• (3) When the strength of the connected element must be developed, a weld symbol without a dimension and without CJP in its tail designates a weld that will develop the adjacent base metal strength in tension and shear.

(4) Any special end return requirements.

If standard welding symbols are insufficient to convey the design intent, special conditions should be fully explained by added notes or details.

When other methods are used, the EOR must provide data concerning the loads, including shears, moments, axial forces, and transfer forces, that are to be resisted by the individual members and their connections, sufficient to allow the selection, completion, or design of the connection details.

In some cases, connection design is dependent on multiple load combinations in the members, and these member loads must be provided. Specific examples include the following:

• $P_{r}$, the required axial strength, necessary to determine the web panel-zone shear strength in Section J10.6
• • The required axial and flexural strengths in a hollow structural section (HSS) chord at a joint necessary to determine strength relative to many limit states in Section J10 and Chapter K

When the EOR intends to allow an experienced steel detailer to select or complete the structural steel connections (described as Option 2 in the Code of Standard Practice), the EOR is the only engineer involved in the process. The experienced steel detailer is not expected to perform engineering calculations.

When structural steel connection design is delegated to be designed by a licensed engineer (described as Option 3 in the Code of Standard Practice), the EOR must provide project-specific schematic connection details based on realistic design forces to define the design intent and sufficient information, provided in writing, for the delegated connection designer (the licensed engineer to whom the work is delegated) to understand the scope and nature of the delegated work and its relationship to the overall design. The information that is required to perform the delegated design shall be commensurate with the nature and complexity of the project. It may include not only member loads, but also references to technical articles, journals, and other performance standards; or other relevant and related information, as appropriate, to understand the design intent and perform the required calculations.

Delegated structural steel connection design does not serve as a peer review of the EOR’s design documents.

The EOR must review and approve the substantiating connection information and the resulting shop drawings, or other documents that are submitted, for conformance with the specified criteria and compatibility with the design intent. The EOR is the final authority and responsible party for the connections utilized on the project.

Design of Member Reinforcement. Ideally, members should be sized for local effects at locations of structural steel connections such that local reinforcement is not required. If members are not sized for local effects at locations of structural steel connections, member reinforcement may be required to satisfy strength and equilibrium of forces through the connection. Such local member reinforcement may include column stiffeners, web doubler plates, beam bearing stiffeners, HSS joint cans, external chord stiffeners, and all other forms of reinforcement. Methods for designing and fabricating such reinforcing are well-established and addressed in this Specification for some cases. For other cases, such as for connections involving HSS, methods for designing and fabricating reinforcing are not addressed and can be complex. In any case, such local reinforcement (or when structural steel connection design is delegated, the potential need for such local reinforcement) is addressed in the Code of Standard Practice and must be identified in the design documents.

A4.2 Structural Design Documents and Specifications Issued for Any Purpose

Structural design documents are commonly issued for various purposes on a structural steel project. These include, but are not necessarily limited to, issued for construction, for permit, for fabrication and erection (for example, commencing work on the project by the fabricator and erector, ordering structural steel, and commencing work on shop drawings, etc.), or for all or a portion of the project as specified. They can also be issued for preliminary or intermediate budget pricing, an initial or final guaranteed maximum price (IGMP or GMP), for bidding, and for contract documents, as defined in the Code of Standard Practice. The intent of this section of the Specification is that the EOR and the various project stakeholders fully communicate and have a common understanding of the purpose for which the documents are being issued and that such documents be clearly labeled for that purpose and dated. It is anticipated that the purpose and date would be applied in the title block of each drawing that is issued, which has been customary in past and current practice on many projects. If

the releasing entity (for example, owner, general contractor, construction manager, or other party) releases the documents for bidding, negotiating for, or executing a contract, this Specification requires that documents released be so labeled by the EOR for such purpose. The EOR is the only party that fully understands and can interpret the design status and whether sufficient information is shown on the documents for the purpose of bidding or contract. Release of documents for bidding or contract that are not sufficiently complete could have life safety implications if the structural design is not advanced to allow proper definition of the scope of work. The issuance of design documents and specifications for construction by the EOR and the requirements listed under Section A4.1 are deemed to protect life safety and public welfare. It is recommended that structural design documents issued for permit, ordering structural steel, or placing a mill order also meet the stated requirements for documents issued for construction. Issuance of structural design documents for these purposes, when the documents are partially complete and the design is evolving, requires good communication among the parties and careful coordination of handling items that are not yet designed and shown on the design documents. While ideally all design information should be provided at the start of construction, this is not always practical or possible with an accelerated design schedule. The safety of the structure mandates that the requirements for design documents in this section be satisfied before construction on the specified portion of the structure is initiated. Revisions to design documents may require adjustments to the contract price and schedule. However, such contractual matters are beyond the scope of the Specification and are addressed in the Code of Standard Practice. Refer to the Code of Standard Practice Section 3.2 for requirements when issuing structural design documents and specifications that serve as the basis for contract documents as defined therein.