Plan Review: 129 Issues Found

Summary: The foundation plan specifies a continuous footing (CF30) with a top elevation tag of '98'-0"' while simultaneously calling out a bottom of footing elevation of 'BO FTG EL=98'-0"' at the same location. This geometry yields a physical foundation depth of zero inches. This explicitly contradicts ACI 318-19 Section 13.3.1.2, which requires the overall depth of the foundation to be selected such th...

Why it matters: A foundation with zero depth is physically impossible and signifies a severe drafting or coordination error. If left uncorrected, it will cause immediate delays on site, as the contractor cannot pour a foundation with no thickness, nor can the minimum 6-inch effective depth for bottom reinforceme...

Suggested next step: Please clarify the intended Top of Footing and Bottom of Footing elevations at locations where 'BO FTG EL=98'-0"' is currently specified beneath 'CF30 / 98'-0"' callouts. Confirm that the revised overall foundation depth provides at least 6 inches of effective depth for bottom...

RFI draft: Please clarify the intended Top of Footing and Bottom of Footing elevations at locations where 'BO FTG EL=98'-0"' is currently specified beneath 'CF30 / 98'-0"' callouts. Confirm that the revised overall foundation depth provides at least 6 inches...

Summary: The drawing designates the seismic force-resisting system as 'BUILDING FRAMING SYSTEM – STEEL INTERMEDIATE MOMENT FRAMES' with Seismic Design Category D and R = 4½. Per ASCE 7-16 Table 12.2-1 (referenced in Section 12.8.1.1 for system selection and R factor determination), Steel Intermediate Moment Frames are designated 'NP' (Not Permitted) for Seismic Design Categories D, E, and F. This system...

Why it matters: This is a fundamental lateral system selection error that will result in plan review rejection by the authority having jurisdiction. Correcting the system from Steel IMF to Steel SMF per AISC 341-16 will require prequalified moment connections per AISC 358, heavier beam and column member sizes, m...

Suggested next step: Request the structural engineer confirm the permitted seismic force-resisting system for SDC D per ASCE 7-16 Table 12.2-1. Clarify whether the lateral system will be upgraded to Steel Special Moment Frames (R = 8, Cd = 5.5) per AISC 341-16, or whether an alternative permitted ...

RFI draft: Request the structural engineer confirm the permitted seismic force-resisting system for SDC D per ASCE 7-16 Table 12.2-1. Clarify whether the lateral system will be upgraded to Steel Special Moment Frames (R = 8, Cd = 5.5) per AISC 341-16, or whe...

Summary: Multiple stair connection details on this sheet show fully rigid connections between HSS stringers and the supporting structure at floors and landings. Detail B5 (Stair Stringer at Landing) shows CJP welds connecting the HSS stringer to the landing HSS members via an HSS filler. Detail D5 (Stair Stringer at Landing) shows a CJP weld connecting the stringer to the landing structure and a 3/16 fi...

Why it matters: Rigid stair connections that do not accommodate inter-story drift will induce large axial forces in the stair stringers acting as diagonal braces between floors during a seismic event. This can cause connection failure, stringer buckling, or damage to the supporting structure, potentially blockin...

Suggested next step: Request clarification on whether the egress stairs are intended to accommodate seismic relative displacements per ASCE 7-16 Section 13.5.10. If the stairs are not part of the SFRS, the stair-to-structure connections at floors and landings should be revised to include sliding c...

RFI draft: Request clarification on whether the egress stairs are intended to accommodate seismic relative displacements per ASCE 7-16 Section 13.5.10. If the stairs are not part of the SFRS, the stair-to-structure connections at floors and landings should b...

Summary: The drawing specifies a Seismic Response Coefficient of Cs = 0.068 and a Design Base Shear of V = 0.068W for a system with SDS = 0.408g, R = 4 1/2, and Ie = 1.0. According to ASCE 7-16 Eq. 12.8-2, the base calculation for Cs is SDS / (R / Ie), which evaluates to 0.408 / 4.5 = 0.0907. The listed value of 0.068 mathematically matches the use of an R-factor of 6.0, contradicting the stated R = 4 1...

Why it matters: Understating the Seismic Response Coefficient by approximately 25% (0.068 instead of 0.0907) results in a proportionally undersized lateral force-resisting system. This directly violates building code safety requirements and significantly compromises the structural integrity of the building durin...

Suggested next step: Please verify the calculation for the Seismic Response Coefficient (Cs) and Design Base Shear (V). Based on the stated SDS = 0.408G and R = 4 1/2, Cs should be 0.0907 per ASCE 7-16 Eq. 12.8-2. If the lower Cs value of 0.068 is governed by the approximate fundamental period (T)...

RFI draft: Please verify the calculation for the Seismic Response Coefficient (Cs) and Design Base Shear (V). Based on the stated SDS = 0.408G and R = 4 1/2, Cs should be 0.0907 per ASCE 7-16 Eq. 12.8-2. If the lower Cs value of 0.068 is governed by the appr...

Summary: The user focus specifies that this structure utilizes Steel Intermediate Moment Frames per AISC 341-16. ASCE 7-16 Section 14.1.2.2 requires such seismic systems to be detailed per AISC 341. Drawing Note 2 confirms that lateral stability depends on these moment frames, and the framing plan specifies "HSS4x4x3/16 POST" for perimeter columns and "HSS6x6x1/4" for perimeter beams. Under AISC 341-16,...

Why it matters: Using non-compact structural tubes in an Intermediate Moment Frame prevents the system from safely dissipating seismic energy. The columns and beams could experience premature local buckling during an earthquake before ductile yielding occurs, leading to a brittle failure and severely compromisin...

Suggested next step: Please revise the HSS post and beam sizing to sections with thicker walls (e.g., HSS4x4x1/4 or thicker for columns) that satisfy the Moderately Ductile width-to-thickness ratio requirements of AISC 341-16 for Intermediate Moment Frames.

RFI draft: Please revise the HSS post and beam sizing to sections with thicker walls (e.g., HSS4x4x1/4 or thicker for columns) that satisfy the Moderately Ductile width-to-thickness ratio requirements of AISC 341-16 for Intermediate Moment Frames.

Summary: Detail C3 details an "HSS BEAM TO HSS BEAM" connection using a 3/16" fillet weld on the top flange and a CJP weld on the bottom flange, but entirely omits welding for the webs (no 'all-around' symbol or separate web weld is specified). Because shear forces in an HSS are carried primarily by the vertical webs, failing to weld the webs prevents the connection from developing the required shear st...

Why it matters: Omitting web welds disrupts the continuous load path for gravity and seismic shear forces. The shear load would be forced through the top and bottom flanges, causing out-of-plane bending and severe localized stresses that could lead to premature, brittle failure of the connection during a seismic...

Suggested next step: Please revise Detail C3 to clearly specify welds for the HSS webs to ensure full shear transfer. If this connection is part of an intermediate moment frame, please specify CJP welds all around or an equivalent prequalified moment connection detail that complies with AISC 341.

RFI draft: Please revise Detail C3 to clearly specify welds for the HSS webs to ensure full shear transfer. If this connection is part of an intermediate moment frame, please specify CJP welds all around or an equivalent prequalified moment connection detail...

Summary: The low roof framing plan designates "W24x68 MOMENT FRAME" members that are supported by and frame directly into continuous "W12x96" beams (girders). IBC Section 2205.2.1.1 requires that moment connections in intermediate moment frames be prequalified beam-to-column connections in accordance with AISC 341 or AISC 358. Because the drawing details a beam-to-girder moment frame configuration inste...

Why it matters: Beam-to-girder moment connections are not prequalified under AISC 358 for seismic force-resisting systems. Using them in an intermediate moment frame without qualification testing compromises the lateral stability of the building and violates seismic detailing requirements. This will result in pl...

Suggested next step: Please clarify if the "W24x68 MOMENT FRAME" members are part of an R=3 system not specifically detailed for seismic resistance. If they are part of an intermediate moment frame, please revise the framing layout to provide prequalified beam-to-column moment connections per AISC...

RFI draft: Please clarify if the "W24x68 MOMENT FRAME" members are part of an R=3 system not specifically detailed for seismic resistance. If they are part of an intermediate moment frame, please revise the framing layout to provide prequalified beam-to-colu...

Summary: The framing plan specifies "W24x68 MOMENT FRAME" and "W30x90 MOMENT FRAME" lines that are supported by "HSS6x6x1/4" columns. The 6-inch face width of the HSS columns is narrower than the flange widths of both the W24x68 (approx. 8.97 inches) and W30x90 (approx. 10.4 inches) beams. This physical incompatibility means the beam flanges will overhang the column face, making standard direct beam-to-...

Why it matters: IBC Section 2205.2.1.1 requires that beam-to-column moment connections in intermediate moment frames be prequalified in accordance with AISC 341 or AISC 358. Prequalified direct moment connections (such as WUF-W or RBS) require the column face to be at least as wide as the beam flange. Without cu...

Suggested next step: Please review the column sizes along the moment frame lines. The specified W24x68 and W30x90 beams have flanges wider than the HSS6x6 columns, which prevents the use of standard prequalified moment connections. Recommend revising the columns to appropriate W-shapes or larger H...

RFI draft: Please review the column sizes along the moment frame lines. The specified W24x68 and W30x90 beams have flanges wider than the HSS6x6 columns, which prevents the use of standard prequalified moment connections. Recommend revising the columns to ap...

Summary: Based on the user focus requiring evaluation of Intermediate Moment Frames (IMF), IBC 2021 Section 2205.2.1.1 states that IMF beam-to-column connections must be prequalified per AISC 341/358 or tested. General Note 2 states that lateral stability depends on the moment frames. The plan specifies perimeter columns as 'HSS4x4x3/16 POST' and perimeter beams as 'HSS6x6x1/4'. A 6-inch wide beam frami...

Why it matters: Failing AISC 341 seismic compactness requirements invalidates the seismic lateral design. Furthermore, attempting to fabricate a moment connection where the beam is wider than the supporting column will require highly non-standard, untested custom collar assemblies, leading to immediate fabricati...

Suggested next step: Revise the moment frame member sizes. Increase the column size to be equal to or wider than the beam (e.g., at least HSS 6x6) and ensure the column wall thickness meets the Moderately Ductile Member b/t limits required by AISC 341 for Intermediate Moment Frames. Alternatively,...

RFI draft: Revise the moment frame member sizes. Increase the column size to be equal to or wider than the beam (e.g., at least HSS 6x6) and ensure the column wall thickness meets the Moderately Ductile Member b/t limits required by AISC 341 for Intermediate...

Summary: Detail B2 for the Intermediate Moment Frame (IMF) connection specifies a cap plate to be welded to the column using a 3/8" fillet weld on '3 SIDES'. The cap plate functions as a continuity plate at the top of the column. According to IBC Section 2205.2.1.2, IMF connections must be prequalified per AISC 341, which strictly mandates that continuity plates be welded to column flanges with Complete...

Why it matters: A 3/8" fillet weld cannot develop the full plastic yield capacity of the continuity plate in the same manner as a CJP groove weld. During a seismic event, this inadequate weld could fail prematurely, preventing the intended plastic hinge from forming in the beam and severely compromising the late...

Suggested next step: Please revise Detail B2 to specify a Complete Joint Penetration (CJP) groove weld for the connection of the cap plate to the column flanges, as required for continuity plates in prequalified Intermediate Moment Frames per AISC 341.

RFI draft: Please revise Detail B2 to specify a Complete Joint Penetration (CJP) groove weld for the connection of the cap plate to the column flanges, as required for continuity plates in prequalified Intermediate Moment Frames per AISC 341.

Summary: The Foundation Plan (S-101) provides a callout to detail C2/S-401 near grid H.5, identifying the area's columns as "W14x132" and footings as "F132" and "CF30". However, the corresponding Enlarged Vestibule Foundation Plan (C2/S-401) details the columns in this space as "HSS5x5x1/4" and the footings as "F48A" and "CF24".

Why it matters: A severe mismatch between heavy W-shape columns with massive footings and lighter HSS columns with smaller footings indicates a major coordination failure. This contradiction will cause procurement errors, incorrect material fabrication, and potentially improperly poured foundations if not resolv...

Suggested next step: Please clarify the correct column types and footing sizes for the vestibule area near grid H.5. Should the foundation follow the heavy W-shape columns (W14x132) and larger footings (F132, CF30) shown on S-101, or the HSS columns (HSS5x5x1/4) and smaller footings (F48A, CF24) d...

RFI draft: Please clarify the correct column types and footing sizes for the vestibule area near grid H.5. Should the foundation follow the heavy W-shape columns (W14x132) and larger footings (F132, CF30) shown on S-101, or the HSS columns (HSS5x5x1/4) and s...

Summary: On S-111, moment frame beams are designated to receive shear studs, such as "W24x68 (24) MOMENT FRAME". Detail C3 on S-541 dictates that typical composite shear connectors be equally spaced starting 2" from the support. However, Detail B2 on S-541 establishes a "MARKED PROTECTED ZONE" extending distance "d" (the beam depth, 24") from the column face and states "BEAM CONNECTION NOT ALLOWED IN PR...

Why it matters: Spacing the specified 24 shear studs uniformly starting 2" from the support will place several studs inside the protected zone of the moment frame. Welding studs within the protected zone of an Intermediate Moment Frame is generally prohibited by seismic codes due to the creation of stress concen...

Suggested next step: Please clarify the placement of headed shear studs on moment frame beams. Should the shear studs be omitted within the protected zone distance "d" from the column face to comply with intermediate moment frame detailing requirements?

RFI draft: Please clarify the placement of headed shear studs on moment frame beams. Should the shear studs be omitted within the protected zone distance "d" from the column face to comply with intermediate moment frame detailing requirements?

Summary: The framing plan indicates a Finish Floor elevation of 115'-6" and a Top of Steel elevation of 115'-3", resulting in a total slab thickness (deck + concrete topping) of only 3 inches. However, the specifications require a 3" deep deck with 4 1/2" long shear connectors for composite floors unless noted otherwise. A 3" total slab thickness provides 0" of concrete over the deck flutes and leaves t...

Why it matters: This geometrical impossibility prevents the proper construction of the composite floor. The shear connectors will be exposed, and there is insufficient space for the concrete topping required to provide structural diaphragm action, load distribution, and fire rating. This elevation discrepancy mu...

Suggested next step: Please clarify the correct Top of Steel and Finish Floor elevations for the 2nd floor. Should the Top of Steel be lowered to accommodate the 3" deck and required concrete topping (e.g., minimum 5.25" to 6" total slab thickness), or should the Finish Floor elevation be raised?

RFI draft: Please clarify the correct Top of Steel and Finish Floor elevations for the 2nd floor. Should the Top of Steel be lowered to accommodate the 3" deck and required concrete topping (e.g., minimum 5.25" to 6" total slab thickness), or should the Fini...

Summary: The Reinforcing Steel notes specify that all welded wire fabric shall conform to ASTM A479. ASTM A479 is the Standard Specification for Stainless and Heat-Resisting Steel Bars and Shapes, which is not a welded wire reinforcement specification. The correct ASTM specification for welded wire reinforcement recognized by ACI 318-19 is ASTM A1064 (which superseded ASTM A497). This appears to be a tr...

Why it matters: If the contractor attempts to procure material per ASTM A479 as specified, they will be unable to obtain welded wire fabric since ASTM A479 covers stainless steel bars and shapes for high-temperature applications. This will generate an RFI and delay procurement of welded wire reinforcement needed...

Suggested next step: Request the structural engineer correct the ASTM specification for welded wire fabric. The note currently references ASTM A479 (Standard Specification for Stainless and Heat-Resisting Steel Bars and Shapes). Please confirm the correct specification should be ASTM A1064 (Standa...

RFI draft: Request the structural engineer correct the ASTM specification for welded wire fabric. The note currently references ASTM A479 (Standard Specification for Stainless and Heat-Resisting Steel Bars and Shapes). Please confirm the correct specificatio...

Summary: The CONCRETE PEDESTAL SCHEDULE specifies vertical reinforcement quantities for CP24 and CP60 that do not satisfy the minimum 1% longitudinal reinforcement ratio (0.01Ag) required for columns/pedestals. For CP24 (2'-0" x 2'-0", Ag = 576 sq.in.), 12-#6 bars are specified (As ≈ 5.28 sq.in.), which is less than the required 5.76 sq.in. For CP60 (5'-0" x 5'-0", Ag = 3600 sq.in.), 32-#8 bars are spec...

Why it matters: Falling below the minimum required longitudinal reinforcement area violates code section 10.6.1.1. This minimum limits the effects of creep and shrinkage of the concrete under sustained compressive loads and ensures the compression member has adequate resistance against accidental bending moments.

Suggested next step: Please verify if pedestals CP24 and CP60 are considered oversized per any code exceptions not evaluated here, or revise the vertical reinforcement quantities in the Concrete Pedestal Schedule to meet the minimum 0.01Ag requirement (providing at least 5.76 sq.in. for CP24 and 3...

RFI draft: Please verify if pedestals CP24 and CP60 are considered oversized per any code exceptions not evaluated here, or revise the vertical reinforcement quantities in the Concrete Pedestal Schedule to meet the minimum 0.01Ag requirement (providing at le...