3.2Structural Design Documents and Specifications Issued as Contract Documents

The Code has been modified to clarify the requirements for design documents and specifications issued for construction (refer to the Glossary for the definition of issued for construction) and issued for contract documents (design drawings and/or digital model, where applicable, specifications, and the contract with the fabricator or erector). Documents issued for construction for all or a portion of the work are subject to the requirements of Section 3.1. Design documents issued as the basis of a contract for structural steel fabrication and erection are covered in a new Section 3.2. Section 3.2 now addresses all the items formerly located in Sections 3.1.1 and 3.1.2 of the 2016 Code, including member reinforcement (such as stiffeners, web doubler plates, and beam bearing stiffeners) away from connections and at locations of connections. Any of these items, or other items that are not defined on partially complete documents issued for contract documents as stated in Section 3.2.2 for alternate delivery methods, should be treated as an allowance by the various stakeholders to a contract. The requirements for an allowance are covered in Section 9.1.5, including the commentary, which further explains their purpose and application.

Contract documents can vary greatly in complexity and completeness depending on the delivery method utilized for the project. Nonetheless, the fabricator and erector must be able to rely upon the accuracy and completeness of the contract documents for bidding. This allows the fabricator and erector to provide the owner with bids that are adequate and complete.

This section lists the minimum requirements for contract documents. If partially complete documents are issued for contract documents, the parties (including, but not limited to, the owner, owner's representatives for design and construction, the fabricator, and erector) should collaborate to reach mutual agreement on what information is not specified and document in writing what allowances are to be included with appropriate contingencies for the uncertainty (including allowances for member reinforcement and connections where Option 3 is specified). Any contracts can then be executed according to the provisions of Section 9.1.5 for reconciliation by change order after the design of the missing information is completed. Refer to Commentary Section 9.1.5.

Alternative project delivery methods other than the traditional design-bid-build method generally provide for a condensed schedule for the design and construction of a project in an effort to reduce overall cost of a project. The owner elects to release for construction the structural design documents and specifications, which may be partially complete, at a time that may precede the completion of and coordination with architectural, mechanical, electrical, and other design work and contract documents. The release of the structural design documents and specifications may also precede the release of the General Conditions and Division 1 Specifications.

Release of the structural design documents and specifications to the fabricator for ordering of material constitutes a release for construction. Accordingly, the fabricator and the erector may begin their work based upon those partially complete documents. As the structural, architectural, mechanical, electrical, and other design documents for the project are completed, revisions are likely required in design and/or construction. Thus, when considering these alternative project delivery methods, the owner should evaluate the potential benefits to the project schedule and cost along with the added cost of changes that are likely to occur. A project cost contingency is necessary to allow for these subsequent changes. The potential cost savings to the project is net of the cost of these design and construction changes.

There are three options covered in this Section:

• (1) In Option 1, the ODRD shows the complete design of the connections in the structural design documents. The following information is included:
• (a) All work point locations and connection geometry
• (b) All plate and angle sizes, thicknesses, dimensions, and material grades
• (c) All weld types, sizes, lengths, locations, and strengths
• (d) All bolt sizes, grades, locations, and quantities
• (e) Member setback distances from the specified work point
• (f) Surface preparation at faying surfaces for bolting or for corrosion protection
• (g) Any member end preparation required such as copes, blocks, cuts, or chipping
• (h) In seismic applications, the information specified in ANSI/AISC 341, Section A4.2
• (i) Any member reinforcement required at connections (see Section 3.2.4)
• (j) Consideration of all applicable strength limit states
• (k) Consideration of fit-up and constructability
• (1) Any other items required for consideration in the particular connection design and detailing so that a steel detailer can detail the connection on the fabrication documents

The intent of this approach is that complete design information necessary for detailing the connection is shown in the structural design documents. Typical details are shown for each connection type, set of geometric parameters, and adjacent framing conditions. The steel detailer will then be able to transfer this information to the approval documents, applying it to the individual pieces being detailed.

• (2) In Option 2, the ODRD allows an experienced steel detailer to select or complete the connections. This is commonly done by referring to loads embedded in the digital model, tables or schematic information in the structural design documents, tables in the AISC Steel Construction Manual, or other reference information approved by the ODRD, such as journal papers and recognized software output. Tables and schematic information in the structural design documents should provide such information as weld types and sizes, plate thicknesses, and quantities of bolts. However, there may be some geometry and dimensional information that the steel detailer must develop. The steel detailer will then configure the connections based upon the design loads and other information given in the structural design documents and specifications.

The intent of this method is that the steel detailer will select the connection materials and configuration from the referenced tables or complete the specific connection configuration (e.g., dimensions, edge distances and bolt spacing) based upon the connection details that are shown in the structural design documents.

The steel detailer must be experienced and familiar with AISC requirements for connection configurations, the use of the connection tables in the AISC Steel Construction Manual, the calculation of dimensions, and adaptation of typical connection details to similar situations. Notations of loadings in the structural design documents are only to facilitate selection of the connections from the referenced tables. It is not the intent that this method be used when the practice of engineering is required.

• (3) Option 3 reflects the practice to have a licensed engineer working for or retained by the fabricator design the connections, and recognizes the information required by the fabricator to do this work. The ODRD, who has the knowledge of the structure as a whole, must review and approve the approval documents, and the substantiating connection information that is requested. See Section 4.4 for the approval process.
• When, under Section 3.2.3, the ODRD designates that connections are to be designed by a licensed engineer employed or retained by the fabricator, this work is incidental to, and part of the requirements for fabricating and constructing the steel frame. The licensed engineer performing the connection design is not providing a peer review of the contract documents.

The ODRD reviews the approval documents during the approvals process as specified in Section 4.4 for conformance with the specified criteria and compatibility with the design of the primary structure.

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. Option 3 is not normally specified for connections that can be selected or completed as noted in Option 2 without practicing engineering.

If there are any restrictions as to the types of connections to be used, it is required that these limitations be set forth in the structural design documents and specifications. There are a variety of connections available in the AISC Steel Construction Manual for a given situation. Preference for a particular type will vary between fabricators and erectors. Stating these limitations, if any, in the structural design documents and specifications will help to avoid repeated changes to the approval documents due to the selection of a connection that is not acceptable to the ODRD, thereby avoiding additional cost and/or delay for revising the approval documents.

For Option 2 and Option 3, the structural design documents must indicate the design loads for connections including transfer forces. Transfer forces can be determined using the connection geometry and statics for an individual load combination. However, transfer forces must be explicitly provided by the engineer of record when connection design loads are provided as maximum/ minimum member forces resulting from more than one load combination or resulting from prescriptive rules provided in the contract documents.

The structural design documents must indicate the method of design used as LRFD or ASD. In order to conform to the spirit of ANSI/AISC 360, the connections must be selected using the same method and the corresponding references. Substantiating connection information can take many forms. When Option 2 is designated, the approval documents may suffice unless additional information is requested by the engineer of record. When Option 3 is designated, the substantiating connection information is required and may take the form of hand calculations and/or software output, and any additional information as requested by the ODRD.

When substantiating connection information is required, it is required that representative samples of that information be agreed upon prior to preparation of the approval documents, in order to avoid additional cost and/or delay for the connection redesign and/or revising that might otherwise result.

The ODRD may require that the substantiating connection information be signed and sealed for Option 3. The signing and sealing of the cover letter transmitting the approval documents and substantiating connection information may suffice. This signing and sealing indicates that a licensed engineer performed the work but does not replace the approval process provided in Section 4.4.

A requirement to sign and seal each sheet of the shop and erection drawings is discouraged as it may serve to confuse the design responsibility between the ODRD and the licensed engineer's work in performing the connection design. Such a requirement may not be possible when submitting fabrication and erection models.

When considering member reinforcement, Option 3 is most useful when the ODRD delegates the connection design, but has selected members to eliminate or minimize the need for member reinforcement at connections. Alternatively, the design documents should specify that the determination and design of member reinforcement at connections is delegated to the licensed engineer working for the fabricator. In such cases, the ODRD is required to provide schematic details for member reinforcement with sufficient information for bidding.

When no quantities and details are shown for column stiffeners, web doubler plates, beam bearing stiffeners, and/or other member reinforcement required to satisfy strength and equilibrium of forces through connections, the fabricator’s bid reflects no allowance for these items. Should it subsequently be determined that member reinforcement at connections is required, the provisions of Sections 9.4 and 9.5 then apply.