STRUCTURAL STEEL
PART 1 GENERAL
1.1SECTION INCLUDES
A.Structural steel for bridges and structures
1.2RELATED SECTIONS
A.Section 05822: Elastomeric Bearings
B.Section 09972: Painting for Structural Steel
1.3REFERENCES
A.AASHTO M 111: Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel
Products
B.AASHTO M 270: Structural Steel for Bridges
C.AASHTO LRFD Bridge Construction Specifications
D.AASHTO LRFD Bridge Design Specifications
E.AASHTO/AWS D1.5 Bridge Welding Code
F.ASTM A 194: Carbon Steel, Alloy Steel, and Stainless Steel Nuts for
Bolts for High Pressure or High Temperature Service, or Both
G.ASTM A 370: Mechanical Testing of Steel Products
H.ASTM A 563: Carbon and Alloy Steel Nuts
I.ASTM F 436: Hardened Steel Washers Inch and Metric Dimensions
J.ASTM F 606: Determining the Mechanical Properties of Externally and
Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
K.ASTM F 959: Compressible-Washer-Type Direct Tension Indicators for
Use with Structural Fasteners, Inch and Metric Series
Structural Steel
L.ASTM F 3125: High Strength Structural Bolts, Steel and Alloy Steel, Heat
Treated, 120 ksi (830 MPa) and 150 ksi (1040 MPa) Minimum Tensile Strength, Inch and Metric Dimensions
M.American Institute of Steel Construction (AISC)
N.American Welding Society (AWS)
O.American Society for Nondestructive Testing (ASNT) SNT-TC-1A:
Personnel Qualification and Certification in Nondestructive Testing
P.Research Council on Structural Connections (RCSC) Specification for
Structural Joints Using High-Strength Bolts
Q.Society for Protective Coatings (SSPC)
R.UDOT Structural Steel Construction Manual
1.4DEFINITIONS
A.Main Members – Members on a critical load path that carry bridge dead
and live loads. The loss of capacity of main members would have serious consequences on the structural integrity.
B.Secondary Members – Members other than main members, not designed
to carry primary load.
C.Snug-Tight Condition – The joint condition in which the plies have been
brought into firm contact and each bolting assembly has at least the tightness attained with either a few impacts of an impact wrench, resistance to a suitable non-impacting wrench, or the full effort of an ironworker using an ordinary spud wrench.
D.Refusal of feeler gauge (bolt tension verification) – The condition where
the gaps between the Direct Tension Indicator (DTI) and unturned element or washer, are too small to permit the insertion of a 0.005 inch feeler gauge from the edge of the washer to the shank of the bolt.
E.Visible gap (bolt tension verification) – A gap between the DTI and
unturned element or washer that can be visually identified but refuses the feeler gauge, indicating that the gap is less than 0.005 inch.
F.Non-Redundant Member – A structural member that supports or resists
tension loads for which there is no alternate load path (no load path redundancy). Structural Steel
1.5SUBMITTALS
A.Working Drawings
1.Shop drawings of all fabricated materials for review.
a.The seal of a Professional Engineer (PE) or Professional
Structural Engineer (SE) is not required.
2.Erection Drawings for all structural steel members for review.
a.Fully illustrate the proposed method of erection. Provide
complete details of the process including, but not limited to: 1) Temporary supports, bracing, guys, dead-men, lifting devices, connection details and attachments to bridge members. 2) The schedule and sequence of erection, location of cranes, crane capacities, location of lifting points on the members, member weights, and any other assumed loads. 3) Complete details for all anticipated phases and conditions during erection. 4) Minimum number of items such as main members, secondary members, and connections that must be installed and properly connected to provide structural integrity and stability. 5) Supporting calculations according to the current edition of the AASHTO LRFD Bridge Design Specifications to demonstrate that factored member capacities are not exceeded and final geometry will be correct. 6) Incorporate into the erection drawings the requirements from this Section, Article 3.5.
b.Include supporting engineering calculations.
c.Provide the seal of a PE or SE licensed in the State of Utah
on the drawings and calculations.
3.Drawings for temporary works for review.
a.Design temporary supports and falsework according to the
current edition of the AASHTO LRFD Bridge Construction Specifications, Section 3, Temporary Works
b.Clearly indicate non-redundant steel members when
incorporated into temporary works.
B.Material Submittals
1.Manufacturer’s certificate of compliance for bolts, nuts, and
washers for information.
a.Refer to ASTM F 606 and ASTM F 3125.
Structural Steel
b.Include corresponding lot numbers appearing on the
shipping package, certification, test location, time and date, and results of the testing.
c.Include rotational capacity and proof load test results.
2.Certified mill test reports (MTR) for information.
a.Include all fabricated structure materials, seven calendar
days before fabrication, including materials manufactured outside of the United States.
b.Clearly indicate country of origin on MTR.
3.Charpy V-Notch test results for information. Refer to ASTM A 370.
C.Welding Procedures and Qualifications for review. Include at least the
following:
1.Weld Procedure Specifications and Procedure Qualification
Records as required by the specified AWS Code.
2.Welder Qualification Record for each operator, process, and
position as required by the specified AWS Code.
a.Include a letter or continuity log from the fabricator that
states the qualified welders have been using the process without an interruption of more than six months since being certified.
D.Documentation of AISC Certification for information
1.Fabrication certification according to this Section, Article 2.6.
E.Bolting Procedures for review
1.Bolting procedure for high strength and anchor bolts including at
least the following:
a.Handling, storage and identification of fasteners
b.Preparation of bolted parts
c.Pre-installation verification procedure
1) Not applicable to anchor bolts
d.Installation
1) Diagram and label the components of the fastener assembly. 2) Show the location and orientation of the components. 3) State whether the bolt head or the nut will be turned. 4) Include procedures for both snug tight and slip critical installations. 5) Include specific diagrams and procedures for order that fastener assemblies are to be tightened.
e.Procedures for drawing connecting elements into full contact
with each other.
Structural Steel
f.Inspection
1) Provide tasks the installer is to perform prior to and during bolting installation in order to ensure fastener assembly was properly tightened. 2) Provide tasks for both snug tight and slip critical installations.
g.Personnel responsible for each activity.
2.The RCSC Specifications for Structural Joints Using High-Strength
Bolts is a valuable reference for the development of bolting procedures
3.Request to use self-indicating Direct Tension Indicators if
applicable
F.Bolt Pre-Installation Verification Test Report for information
1.Calibration report for Bolt Tension Measurement Device (BTMD),
dated within 1 year of the submittal, for information
2.Pre-Installation Verification Test Report using Direct Tension
Indicators for each tested assembly.
G.Construction Documentation for information
1.Bolted Field Splice Certification form
2.Bolted Diaphragm Certification form
H.Temporary Works, Structural Steel Construction Report for non-redundant
members for review before placing load on the temporary structure. Include at least the following:
1.Copy of the authorized drawings for temporary works
2.Applicable certifications including a copy of applicable AISC
certifications for the fabricator
3.Welding methods to be used
4.Procedure Qualification Records (PQR) and Welding Procedure
Specifications (WPS)
4.Material certification: mill test reports
5.Welder qualifications
6.Methods for storage, handling and management of welding
consumables
7.List of the Quality Control Personnel including an AWS Certified
Welding Inspector (CWI) for field welding
8.Nondestructive Testing (NDT) personnel qualifications and
certifications according to the latest edition of SNT-TC-1A
9.Records of Nondestructive Testing that was performed and test
equipment calibration data
10.Acceptance of welds by the CWI and NDT technicians
11.Certification by the engineer of record for the temporary structure,
that the temporary structural steel members have been constructed as shown on the signed and sealed drawings Structural Steel
1.6ERECTOR QUALIFICATIONS
A.An AISC Certified Erector with Bridge Endorsement is preferred when
erecting, bolting, and welding bridge framing members:
1.7QUALIFICATIONS FOR TEMPORARY STRUCTURAL STEEL SUPPORT
SYSTEMS WITH NON-REDUNDANT MEMBERS
A.AWS Certified Welding Inspector
B.Nondestructive Testing personnel
1.Must be an NDT level 2 certified technician
PART 2 PRODUCTS
2.1STRUCTURAL STEEL
A.Follow AASHTO LRFD Bridge Construction Specifications, Article 11.3,
unless otherwise indicated.
B.Do not use stock steel purchased from a warehouse for use in a main
member without conducting mill inspection, unless authorization is given.
2.2HIGH STRENGTH FASTENERS
A.Use bolts, nuts, and washers displaying the manufacturer’s markings.
B.Bolts
1.Refer to ASTM F 3125.
2.Use Grade A325 Type 1 or 3.
C.Nuts
1.Refer to ASTM A 194 or ASTM A 563.
2.Use heat-treated Grades DH and 2H, except use Type DH3 nuts
when Type 3 bolts are shown.
D.Washers
1.Refer to ASTM F 436.
E.Direct Tension Indicator (DTI) Washers
1.Refer to ASTM F 959.
Structural Steel
2.Self-indicating DTIs may be used when authorized in the bolting
procedure.
a.Use of feeler gauges to indicate bolt tension in self-indicating
DTIs is required as determined by the Engineer
F.Invoke the ASTM F 3125 Supplementary S4 requirement and test bolts,
nuts and washers for rotation-capacity.
a.Report a rotational capacity lot.
2.3ELASTOMERIC BEARINGS AND ANCHORAGES
A.Refer to Section 05822.
2.4APPROACH SLAB DRAIN ANGLES AND GRATES
A.Refer to AASHTO M 270, Grade 36, or as shown.
B.Hot-dip galvanize after fabrication. Refer to AASHTO M 111.
2.5SHOP INSPECTION
A.Notify Engineer immediately upon placing the fabrication order to allow
time for shop inspection.
1.In-state work requires 7 days advanced notice; out-of-state work
requires 30 days advanced notice.
2.Schedule shop inspection before beginning fabrication.
2.6FABRICATION
A.Fabricate according to AASHTO LRFD Bridge Construction Specifications
AASHTO/AWS D 1.5.
B.The fabricator must be certified by AISC as a Certified Bridge Fabricator –
Advanced (ABR) if fabricated structural steel will be part of a bridge structure, except as follows:
1.Railings, grates, grate frames, and drain pipes may be fabricated
by an AISC certified Highway Component Manufacturer (CPT).
C.Supply enough fastener assemblies for erection and pre-installation
verification tests for each bolting crew.
D.Surface preparation of steel
1.Painted Steel
a.Refer to Section 09972.
Structural Steel
2.Unpainted Weathering Steel
a.Meet blast clean qualifications and surface preparation
requirements for painted steel according to Section 09972.
b.Construct so that erection marks on the steel are not visible
after the structure is completed.
c.Commercially blast clean the following surfaces according to
SSPC-SP 10: 1) I-girders
a.Underside of the exterior portion of the top
flange of fascia girders and underside of bottom flange of all girders
b.Exterior portion of web of fascia girders
c.Top side and outside edge of the exterior
portion of the bottom flange of fascia girders
d.All welded surfaces
2) Trusses
a.Top chord, diagonals, and top bracing
b.Exposed surfaces of bottom chord, floor
beams, and bottom bracing
c.All welded surfaces
d.Commercially blast clean all other surfaces according to at
least SSPC-SP 6.
e.Develop even patina at completion of welding repair and
after surface has been verified by the Engineer. 1) Apply at least three uniform applications of water mist at 24 hour intervals to initiate even weathering.
E.Fabricate non-redundant members in temporary support structures
according to the AASHTO Construction Specifications, Section 11, Steel Structures
1.Fabricate components in an AISC-certified shop with a Fracture
Control Endorsement.
2.Fabricate components according to the AASHTO/AWS D1.5 Bridge
Welding Code except that Clause 12 base metal material requirements do not need to be invoked.
PART 3 EXECUTION
3.1INSTALL HIGH STRENGTH FASTENERS
A.Use DTI washers to indicate bolt tension.
1.Follow the manufacturer’s methods and procedures as modified in
this Specification
Structural Steel
2.Bolts embedded in concrete:
a.Place DTI washer on the side of the connection that will not
be embedded in concrete if fastener assembly will be partially embedded.
b.Place DTI washer on the more easily inspectable side of the
connection if the fastener assembly will be entirely embedded in concrete.
c.Do not place concrete until the inspector has verified that all
fasteners are properly tightened.
B.Store the bolts and nuts in the original containers until used.
1.Protect from dirt and moisture.
2.Remove only as many fasteners from protected storage as are
anticipated to be tightened during a work shift.
a.Return unused fasteners to protected storage at the end of
each work shift.
3.Clean and re-lubricate fasteners that accumulate rust or dirt.
a.Use manufacturer’s recommended lubricant.
C.Perform pre-installation verification tests to verify fastener assemblies,
tools, and installers can achieve minimum pretension using their means and methods before beginning field bolting operations.
1.General requirements
a.Conduct testing according to the pre-installation verification
included in the authorized bolting procedures.
b.Provide a calibrated BTMD for bolt testing at the job site
such as a Skidmore-Wilhelm Calibrator. 1) Calibrate or confirm the accuracy of the BTMD at least annually.
c.Perform verification tests for each combination of rotation
capacity lot, assembly configuration and DTI lot using the tools and installation methods to be used in production.
d.Perform verification testing for each bolting crew.
e.Perform verification testing before beginning erection and
whenever the condition of the fasteners or the knowledge or practice of the installer is in question.
f.Do not use an impact wrench.
g.Prevent the unturned element from rotating
2.Test assembly to the verification bolt pretension load.
a.Always place a hardened washer (ASTM F 436) between the
DTI and the turned element.
Structural Steel
b.Install the bolt, nut, washer and DTI assembly into a
calibrated BTMD so that at least three and no more than five threads are located between the bearing face of the nut and the bolt head. 1) When the bolts are too short to satisfy this requirement refer to this Section, Article 3.1 B6.
c.Tighten the assembly to the snug-tight condition.
d.Tighten the bolt until the achieved tension read by the BTMD
is equal to the required verification pretension listed in Table 1.
e.Record the number refusals of the 0.005 inch tapered feeler
gauge in the spaces between the protrusions in a Pre- Installation Verification Test Report using Direct Tension Indicators form. 1) An example Pre-Installation Verification Test Report is available on the UDOT website. Refer to http://www.udot.utah.gov/go/standardsreferences.
3.Continue the test on the fastener assembly to the full refusal
condition.
a.Tension the bolt further until the feeler gauge is refused at all
spaces and a visible gap is remaining in at least one space.
b.Record the tension at this condition.
c.Test the threads by removing the bolt from the BTMD and
running the nut down by hand for the complete thread length of the bolt excluding thread run-out.
Table 1 Verification Bolt Pretension Bolt Size Verification Tension (kips)
(inch)Grade A325
0.5 13 0.625 20 0.75 29 0.875 41 1.0 54 1.125 67 1.25 85 1.375 102 1.5 124 The above values are 5% higher than the required pretension values used for design, and are rounded to the nearest kip.
Structural Steel
4.Evaluate the pre-installation verification testing for failure. The
following conditions indicate pre-installation verification testing failure:
a.The “Maximum Verification Refusals” in Table 2 are
exceeded at the verification bolt pretension
b.The nut cannot be run down for the full thread length and the
final tension exceeds 95 percent of the peak tension measured during rotation capacity testing of the fastener lot. Refer to this Section, 2.2 F1c.
Table 2 DTI 0.005 inch Feeler Gauge Refusal Requirements Maximum Verification Minimum Installation Refusals Refusals DTI Coated DTIs Coated DTIs spaces All other All other under turned under turned cases cases element element 4 3 2 3 3 5 4 2 4 3 6 5 3 5 4 7 6 3 6 4 8 7 4 7 5 9 8 4 8 5
5.Repeat pre-installation verification process until a total of three
bolting assemblies have been successfully tested.
a.Two failed tests indicates a failure or incompatibility with the
combination of fastener assembly, tools and installer.
6.When the fastener-grip length is too short to be tested in a BTMD
use the following procedure.
a.Substitute longer “surrogate” bolts for the verification bolt
pretension test. Refer to this Section, Article 3.1 B2.
b.Use the combination of bolt, nut, washer, and DTI lots to be
used in the work and substitute a steel plate for the BTMD for the full refusal condition test. Refer to this Section, Paragraph 3.1 C3.
7.Follow the manufacturer’s instructions to verify self-indicating
feature if self-indicating DTIs are used.
D.Install fasteners according to the authorized bolting procedure, the Pre-
Installation Verification Test Reports and the following:
1.Complete the Bolted Field Splice Certification form as fastener
tightening progresses for all girder field splices. Refer to http://www.udot.utah.gov/go/standardsreferences for the form.
Structural Steel
2.Complete the Bolted Diaphragm and Cross Frame Member
Certification form. Refer to http://www.udot.utah.gov/go/standardsreferences for the form.
3.Use drift pins to align bolt holes and maintain dimensions and
camber of the member.
4.Prevent the unturned element from rotating when tightening
fastener assemblies.
5.Tighten fastener assemblies progressively from fixed or rigid points
to the free edges.
6.Insert bolts in open holes with washers and hand tighten.
7.Tighten at least 50 percent of the fastener assemblies to the snug-
tight condition.
8.Remove drift pins and replace with bolts.
9.Tighten the remaining fastener assemblies to the snug-tight
condition.
a.Verify that the number of DTI spaces refusing a 0.005 inch
feeler gauge does not exceed the maximum verification refusals in Table 2. 1) Replace assemblies that do not meet Table 2 requirements.
10.Fully tighten 50 percent of the fastener assemblies for field splices
and diaphragms before release of crane or removal of shoring.
a.The number of feeler gauge refusals must meet or exceed
the minimum installation refusals in Table 2 with a visible gap remaining in at least one of the DTI spaces.
b.Replace fastener assemblies with no visible gap remaining.
11.Tighten all fastener assemblies to full tension.
a.The number of feeler gauge refusals must meet or exceed
the minimum installation refusals in Table 2 with a visible gap remaining in at least one of the DTI spaces
b.Replace fastener assemblies with no visible gap remaining.
12.Replace fastener assemblies if appearance of the installed DTIs
are not according to the manufacturer’s instructions when self- indicating DTIs are used instead of feeler gauge to indicate tension.
3.2FIELD WELDING
A.Weld according to AASHTO/AWS D1.5.
B.Meet the same requirements as shop welds.
C.Comply with welding procedures and inspection requirements.
1.Refer to the UDOT Structural Steel Construction Manual.
D.Welding operators must be certified according to the specified AWS Code.
1.Refer to the UDOT Structural Steel Construction Manual.
Structural Steel
3.3PAINTED STRUCTURAL STEEL
A.Paint all structural steel not designated as unpainted weathering steel.
1.Refer to Section 09972.
3.4UNPAINTED WEATHERING STEEL
A.Clean girders of debris after deck concrete is placed.
1.Redevelop patina as needed.
3.5TEMPORARY STRUCTURAL STEEL SUPPORT SYSTEMS WITH
NON-REDUNDANT MEMBERS
A.Weld according to AASHTO/AWS D1.5 except Clause 12 material
requirements.
B.Inspect welds according to AWS D1.5 unless noted otherwise.
1.For fillet and partial penetration welds, verify proper size and profile
and perform magnetic particle testing.
2.For full penetration groove welds, perform ultrasonic and
radiographic testing as required.
C.An AWS Certified Welding Inspector must inspect the welds.
3.6ERECTION
A.Maintain responsibility for girder erection during each stage of construction
including the protection of structural steel members, the workers, and the traveling public.
B.Erect structural steel members according to the authorized erection
drawings and in a manner that prevents damage to elements of the structure.
1.Follow match-marks.
C.Temporarily support, anchor, and brace main members such as girders
during erection to produce the proper alignment and camber in the completed structure.
1.Install cross frames and diagonal bracing as necessary to provide
stability and correct geometry.
2.Provide temporary bracing or stiffening devices if necessary during
each erection stage.
3.Support, anchor, and brace erected superstructure members as
detailed in the authorized erection drawings before allowing traffic under the bridge. Structural Steel
D.Provide additional materials that are required to keep both the temporary
and final stresses within the allowable limits used in design.
E.Handle materials so that no parts will be bent, broken, distorted or
otherwise damaged.
F.Remove dirt and debris from bearing surfaces and surfaces that will be in
permanent contact before the members are assembled.
G.Do not open traffic under a partially erected bridge superstructure unless
allowed in the authorized erection drawings.
END OF SECTION
Structural Steel
Structural Steel in other states
Utah revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.
Source: Utah Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 1120–1133 of 1,331.
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