Plan Review: 267 Issues Found

Summary: Detail 3 specifies a sliding connection using "3/4" Ø A325 BOLTS" and instructs the contractor to "HAND TIGHTEN NUT ON BOLT, BACK OF 1/4 TURN AND TACK WELD NUT TO BOLT." A325 bolts are quenched and tempered high-strength fasteners. Applying heat via tack welding alters their metallurgical properties, destroying the heat treatment and severely reducing the bolt's strength and ductility.

Why it matters: Welding high-strength fasteners is universally prohibited in structural steel construction because it compromises the structural integrity of the connection, creating a high risk of brittle failure under load. This detail will cause the connection to be rejected during special inspections.

Suggested next step: Please advise if an approved alternative mechanical locking method (such as using a locknut, jam nut, or burring the threads) should be utilized in lieu of tack welding to prevent the nut from backing off while preserving the integrity of the A325 bolts.

RFI draft: Please advise if an approved alternative mechanical locking method (such as using a locknut, jam nut, or burring the threads) should be utilized in lieu of tack welding to prevent the nut from backing off while preserving the integrity of the A325...

Summary: Detail 11 on the drawings specifies "FULLY THREADED AB" and "PARTIALLY THREADED STUD" as cast-in anchors for the embed plate. According to ACI 318-14 Section 17.1.3, the design provisions for cast-in anchors apply only to "Headed studs and headed bolts" and "Hooked bolts". Straight, fully threaded rods and partially threaded studs without specified heads or nuts at their embedded ends do not sa...

Why it matters: Without forged heads or heavy hex nuts at the embedded ends, these anchors will rely entirely on bond strength, which ACI 318 Chapter 17 does not permit for the design of cast-in anchors. This detailing error creates a critical risk of premature pullout failure under tensile loads, which would se...

Suggested next step: Please revise the anchor bolt and stud callouts to explicitly specify headed studs, headed bolts, or threaded rods with heavy hex nuts at the embedded ends to comply with ACI 318-14 Section 17.1.3 requirements for cast-in anchors.

RFI draft: Please revise the anchor bolt and stud callouts to explicitly specify headed studs, headed bolts, or threaded rods with heavy hex nuts at the embedded ends to comply with ACI 318-14 Section 17.1.3 requirements for cast-in anchors.

Summary: Detail 8 specifies cast-in anchors as "3/4" Ø NELSON CPL PARTIALLY THREADED STUD" welded to the embed plate, and "FULLY THREADED AB" without specifying a head or heavy hex nut at the embedded end. A partially threaded stud or fully threaded rod lacks a head. ACI 318-14 Section 17.1.3 explicitly limits the design of cast-in tension and shear anchors to headed studs, headed bolts, and hooked bolt...

Why it matters: Relying on the bond strength of straight threaded anchors for a braced frame base plate connection could result in catastrophic tension or overturning failure. The specified "Nelson CPL" studs are coupler studs without heads, providing virtually no structural anchorage capacity in concrete.

Suggested next step: Clarify if standard headed shear studs (e.g., Nelson H4L) should be used instead of partially threaded studs, and confirm if heavy hex nuts are required at the embedded ends of the fully threaded anchor bolts to provide mechanical anchorage. Revise the detail to conform to ACI...

RFI draft: Clarify if standard headed shear studs (e.g., Nelson H4L) should be used instead of partially threaded studs, and confirm if heavy hex nuts are required at the embedded ends of the fully threaded anchor bolts to provide mechanical anchorage. Revis...

Summary: Detail 3 explicitly instructs the contractor to "BREAK STIRRUP AT BASE PLATE AND COLUMN" for the #5 transverse reinforcement. ACI 318-14 Section 25.7.1.1 strictly requires that all stirrups "shall be anchored at both ends." Breaking a stirrup loop at the column/base plate without detailing proper anchorage (such as standard hooks engaging longitudinal bars) leaves unanchored free ends, which di...

Why it matters: Transverse reinforcement that is not securely anchored at both ends cannot effectively develop its yield strength to resist shear forces or confine the concrete. This compromises the structural integrity of the concrete pilaster directly beneath a highly loaded braced frame base plate, significan...

Suggested next step: Please revise the detail to ensure shear reinforcement remains fully anchored. Clarify if continuous stirrups can be accommodated, or provide detailing for overlapping U-stirrups with standard hooks engaging peripheral longitudinal bars on both sides of the steel column in acc...

RFI draft: Please revise the detail to ensure shear reinforcement remains fully anchored. Clarify if continuous stirrups can be accommodated, or provide detailing for overlapping U-stirrups with standard hooks engaging peripheral longitudinal bars on both si...

Summary: The structural drawing specifies the design dead load criteria as "DEAD LOAD = 15 PSF + SELF-WEIGHT". However, the framing is explicitly detailed to support heavy fixed service equipment, including a silencer that weighs up to 15,000 lbs and a chiller stack. ASCE 7-16 Section 3.1.3 mandates that the weight of all fixed service equipment must be included when determining dead loads for design pu...

Why it matters: If delegated connection engineers, steel detailers, or secondary structural suppliers base their component capacities strictly on the "DESIGN LOADS - BAFFLE" schedule, the structure will be severely under-designed for the actual equipment it supports, posing a risk of catastrophic failure.

Suggested next step: Revise the 'DESIGN LOADS - BAFFLE' section to explicitly include the operating weights of the silencer (15,000 lbs max), chiller, and any other fixed service equipment as part of the overall structural dead load criteria, in accordance with ASCE 7-16 Section 3.1.3.

RFI draft: Revise the 'DESIGN LOADS - BAFFLE' section to explicitly include the operating weights of the silencer (15,000 lbs max), chiller, and any other fixed service equipment as part of the overall structural dead load criteria, in accordance with ASCE 7...

Summary: The 'DEFLECTION JOINT KEY PLAN' specifies the combined differential seismic movement for Joint 1 as 1.74" (N-S) and 1.99" (E-W). However, the 'RISK CATEGORY IV COMPONENTS (18" CHILLER PIPES)' schedule restricts the flex connections at EJ Mark 1 to accommodate only 1" of movement in both the perpendicular and parallel directions. This contradicts ASCE 7-16 Section 13.6.2 and 13.6.7, which requir...

Why it matters: If the mechanical flexible connections are designed for only 1" of displacement while the structural joint experiences up to 1.99" of relative seismic displacement, the critical 18" chiller pipes (Risk Category IV) are highly likely to rupture during a design seismic event. This would result in t...

Suggested next step: Please review the flexible connection capacities for the Risk Category IV 18" chiller pipes. Confirm if the flex connections specified for EJ Mark 1 must be increased to at least 1.99" to safely accommodate the maximum combined differential seismic movement listed in the Defle...

RFI draft: Please review the flexible connection capacities for the Risk Category IV 18" chiller pipes. Confirm if the flex connections specified for EJ Mark 1 must be increased to at least 1.99" to safely accommodate the maximum combined differential seismi...

Summary: Detail 3 ("COMMON SUPPLIER HEADER STEEL BEAM BEARING AT TILT-UP PANEL") specifies a steel beam connection to a tilt-up wall using a WT9X23 bracket with '3 1/2" LONG SLOTTED HOLES'. The installation note directs the contractor to 'HAND TIGHTEN NUT ON BOLT, BACK OF 1/4 TURN AND TACK WELD NUT TO BOLT'. This intentionally creates a free-sliding slip connection that provides zero initial lateral res...

Why it matters: Allowing a beam to slip longitudinally severs the continuous lateral load path between the structural tilt-up wall and the diaphragm. During a seismic event, the wall panel can pull away from the framing until the bolt abruptly bottoms out in the 3 1/2-inch slot. This lack of a positive tie induc...

Suggested next step: Please revise Detail 3 to provide a positive, non-sliding connection between the steel beam and the tilt-up wall panel to satisfy ASCE 7 Sections 12.1.4 and 12.11.2.1. If a slip connection is necessary to accommodate thermal movement, please provide a supplementary detail demo...

RFI draft: Please revise Detail 3 to provide a positive, non-sliding connection between the steel beam and the tilt-up wall panel to satisfy ASCE 7 Sections 12.1.4 and 12.11.2.1. If a slip connection is necessary to accommodate thermal movement, please provi...

Summary: Detail 3 specifies the use of '3/4" Ø A325 BOLTS' for the connection and provides installation instructions to 'HAND TIGHTEN NUT ON BOLT, BACK OF 1/4 TURN AND TACK WELD NUT TO BOLT.' A325 bolts are high-strength, quenched and tempered fasteners. Applying heat via welding destroys their heat treatment and metallurgical properties, significantly degrading their strength and causing brittle failure.

Why it matters: Tack welding high-strength bolts is strictly prohibited by AISC 360, which is referenced as the primary standard for steel and composite construction in the building code (Section 14.3.1). If constructed as drawn, the bolts will be critically weakened and will immediately fail special inspection,...

Suggested next step: Remove the requirement to tack weld the A325 bolt nuts. To prevent nut loosening while still allowing for the required slip joint, specify an approved mechanical locking method such as a double nut, deformed threads, or a nylon insert lock nut that does not involve heating the...

RFI draft: Remove the requirement to tack weld the A325 bolt nuts. To prevent nut loosening while still allowing for the required slip joint, specify an approved mechanical locking method such as a double nut, deformed threads, or a nylon insert lock nut tha...

Summary: Detail 3 shows a steel beam bearing connection with "3 1/2" LONG SLOTTED HOLES". The dimension from the center of the hole to the end of the steel beam is specified as "0' - 1 1/2"". A 3.5-inch long slotted hole extends 1.75 inches from its center in both directions. Because the 1.75-inch slot half-length is greater than the 1.5-inch edge distance, the slot will physically cut completely throug...

Why it matters: This geometric impossibility means the connection will have zero edge distance and no bearing capacity in the outward direction. This is a severe detailing error that contradicts standard structural steel fabrication practices and the minimum edge distance requirements mandated by AISC 360, which...

Suggested next step: Revise the connection detail to either decrease the overall length of the slotted hole or increase the horizontal edge distance from the hole center to the beam end. Ensure the remaining material satisfies AISC 360 minimum edge distance requirements past the end of the slot.

RFI draft: Revise the connection detail to either decrease the overall length of the slotted hole or increase the horizontal edge distance from the hole center to the beam end. Ensure the remaining material satisfies AISC 360 minimum edge distance requiremen...

Summary: Detail 3 specifies the use of "3/4" Ø A325 BOLTS" and includes an explicit installation note directing the contractor to "HAND TIGHTEN NUT ON BOLT, BACK OFF 1/4 TURN AND TACK WELD NUT TO BOLT." ASTM F3125 Grade A325 bolts are heat-treated, high-strength structural fasteners.

Why it matters: Tack welding these components is strictly prohibited because the heat input destroys the bolt's necessary heat treatment, degrades its strength, and causes localized embrittlement. Welding on high-strength structural fasteners directly violates the fabrication and erection criteria of AISC 360 (a...

Suggested next step: Remove the instruction to tack weld the A325 bolts. Specify an approved mechanical method to prevent the nut from backing off in the slip connection, such as using a prevailing torque locknut, a double-nut arrangement, or scoring the exposed bolt threads.

RFI draft: Remove the instruction to tack weld the A325 bolts. Specify an approved mechanical method to prevent the nut from backing off in the slip connection, such as using a prevailing torque locknut, a double-nut arrangement, or scoring the exposed bolt ...

Summary: The framing elevation specifies that the top of the CFS wall must be detailed to "ACCOMMODATE 1 1/2" VERTICAL DEFLECTION". However, Detail 4 (Jamb Connection to Roof and Concrete) only provides a "0' - 1"" gap at the deflection head. Furthermore, the typical bent plate section details a 2-inch vertical slot ("0' - 2"") with "CENTER SCREWS IN VERT SLOTTED HOLES, TYP". A screw centered in a 2-inc...

Why it matters: When the roof framing deflects downwards by its design maximum of 1.5 inches, the 1-inch physical gap will close completely, and the centered screws will bottom out in their slotted holes. This forces the roof to transfer structural loads directly into the non-load-bearing CFS jamb studs, likely ...

Suggested next step: Clarify the required vertical deflection for the roof framing. If 1.5 inches of deflection must be accommodated, revise Detail 4 to provide a minimum 1.5-inch deflection gap between the top track and the roof girder. Additionally, increase the length of the slotted hole in the...

RFI draft: Clarify the required vertical deflection for the roof framing. If 1.5 inches of deflection must be accommodated, revise Detail 4 to provide a minimum 1.5-inch deflection gap between the top track and the roof girder. Additionally, increase the len...

Summary: Details 5 and 7 show steel joists oriented perpendicular to the tilt-up wall panels. Because the metal roof deck spans between these joists, the deck's span direction is parallel to the wall. Out-of-plane wall anchorage forces act perpendicular to the wall, meaning they act in the direction perpendicular to the deck span. The details show the metal deck directly attached to a continuous steel a...

Why it matters: Metal roof decks have virtually no axial stiffness or strength in the direction perpendicular to their flutes. Relying on the metal deck as the continuous tie to resist outward seismic wall forces can cause the deck to fold or tear like an accordion, leading to sudden failure of the wall anchorag...

Suggested next step: Provide updated details for wall anchorage at roof locations where joists frame perpendicular to the tilt-up panels (Details 5 and 7). Please detail positive mechanical ties (e.g., HSS struts or steel angles) connecting the tilt-up panel embed plates directly to the joist top ...

RFI draft: Provide updated details for wall anchorage at roof locations where joists frame perpendicular to the tilt-up panels (Details 5 and 7). Please detail positive mechanical ties (e.g., HSS struts or steel angles) connecting the tilt-up panel embed pla...

Summary: Detail 1 (BRACED FRAME DETAIL) contains a note instructing the contractor to provide an "HSS BRACE - NOTCH AS REQUIRED" for the diagonal brace intersecting the 5/8" gusset plate. Notching an HSS diagonal brace removes a portion of its structural cross-sectional area, creating a severe stress concentration. This explicitly violates ASCE 7 Section 12.1.2, which requires that individual members be...

Why it matters: In a seismic force-resisting system, braces are subjected to extreme cyclic tension and compression loads. A notch prevents the brace from yielding uniformly along its length, instead forcing a brittle, localized failure (such as net-section fracture or local buckling) at the notch. This defeats ...

Suggested next step: Remove the instruction to notch the HSS brace. Revise the braced frame connection detail to accommodate the framing geometry without compromising the brace cross-section (e.g., slotting the brace strictly to receive the gusset plate or using a fully welded end-plate connection...

RFI draft: Remove the instruction to notch the HSS brace. Revise the braced frame connection detail to accommodate the framing geometry without compromising the brace cross-section (e.g., slotting the brace strictly to receive the gusset plate or using a ful...

Summary: Detail 3 (HSS BEAM AT HSS BRACE) indicates a continuous horizontal 'HSS BEAM' that is slotted to allow a continuous 3/4" gusset plate to pass through it, as shown by the dashed hidden lines of the plate inside the beam profile. The detail displays only 1/4" fillet welds at the connection between the severed beam and the gusset plate. Slotting a continuous structural beam for a through-plate and...

Why it matters: Beams in braced frames act as critical struts or diaphragm collectors transferring high lateral loads. Breaking the beam's continuity to pass a gusset plate through without providing a fully engineered, full-strength splice (such as complete joint penetration welds that match or exceed the severe...

Suggested next step: Revise the connection detail to eliminate slotting the continuous HSS beam, or provide an engineered splice. If the gusset plate must pass through the beam to maintain working points, the detail must specify complete joint penetration (CJP) welds or appropriate steel splice pl...

RFI draft: Revise the connection detail to eliminate slotting the continuous HSS beam, or provide an engineered splice. If the gusset plate must pass through the beam to maintain working points, the detail must specify complete joint penetration (CJP) welds ...

Summary: ASCE 7 Section 14.2.2.2 (modifying ACI 318 Section 10.7.6.1.6) explicitly requires that when anchor bolts are placed in the top of a column or pedestal, they must be 'enclosed by transverse reinforcement that also surrounds at least four longitudinal bars'. Detail 3 explicitly instructs the contractor to '#5 STIRRUPS AT 6" OC, BREAK STIRRUP AT BASE PLATE AND COLUMN'. Breaking the stirrups preve...

Why it matters: The requirement to enclose anchor bolts with continuous transverse reinforcement is critical for providing confinement and preventing concrete breakout or splitting failure under seismic tension or shear loads. Breaking the ties at the base plate eliminates this confinement, significantly comprom...

Suggested next step: Please revise Detail 3 to provide continuous transverse reinforcement that fully encloses the anchor bolts and longitudinal bars, without breaking the ties at the base plate or column. If the embedded steel section creates a physical conflict, please provide an alternative det...

RFI draft: Please revise Detail 3 to provide continuous transverse reinforcement that fully encloses the anchor bolts and longitudinal bars, without breaking the ties at the base plate or column. If the embedded steel section creates a physical conflict, ple...