SECTION 616
STRUCTURAL STEEL
616.01 GENERAL
The work consists of fabricating, furnishing, delivering and erecting structural steel.
616.02 EQUIPMENT
Reserved
616.03 MATERIALS
Item
Structural Steel and Related Materials
Section
834
Use Welded Stud Shear Connectors meeting the requirements of AASHTO LRFD Bridge
Construction Specifications.
616.04 CONSTRUCTION REQUIREMENTS
A. Work Drawings
Submit work drawings for the fabrication and erection of steel. Show dimensions and sizes
of materials for fabrication, bolt lists for field erection, a match-marking diagram, and a
complete field erection plan.
The Engineer’s review applies only to the requirements for strength, details and
arrangements of parts and details.
B. Shop Inspection
Ensure shop inspection personnel are qualified as specified in the latest AASHTO/AWS D
1.5 Bridge Welding Code.
The Department will not accept welded plate girders without a Department shop inspection.
Provide the Engineer at least three weeks notice before beginning fabrication.
Furnish facilities for the inspection, allow the Inspector access to all areas, and furnish the
inspector at least two 4 inch by 18 inch samples of each grade and brand of structural steel.
D. Fabrication
1. General
Fabricate as specified in the latest AASHTO/AWS D 1.5 Bridge Welding Code except as
modified by this Specification. For structures that carry railroad traffic, fabricate the
structural steel as specified by the AREMA Specifications.
2. Structural Steel
Position shear connectors on splice plates to clear the bolt holes.
The Engineer will allow shop-welded connections of diaphragm angles to gusset plates
in place of the bolted connections. On the shop drawings, indicate which connection
method will be used.
Do not attach any devices that are not shown on the Plans to the structural steel
members during the fabrication and construction process without written permission from
the Department’s Bridge Engineer.
3. Shop Painting
Perform shop painting as specified in Sections 630.02 “Equipment,” 630.03 “Material,”
and 630.04 “Construction Requirements.”
4. Blast Cleaning of Weathering Steel
After fabrication for weathering applications, blast clean the exterior faces of outside
beams or girders, including stiffeners, flanges, and other steel readily exposed to view
as specified in the Steel Structures Painting Council Surface Preparation Specification
“No. 6 Commercial Blast Cleaning,” (SSPC-SP 6). Do not use a corrosion inhibitor.
E. Shop Welding
Shop weld as specified in the latest AASHTO/AWS D 1.5 Bridge Welding Code. Do not use
the electroslag and electrogas welding processes for welding bridge members. Perform
flange-to-web welds and shop welded splices in flanges or webs using the automatic
submerged arc and welding process.
1. Built-up Plate Girders
Cut web plates of built up beams and girders to the prescribed camber with allowance
for shrinkage due to cutting and welding.
Make shop butt welds in the flange plates before final fitting and welding into the girders.
2. Nondestructive Testing
Perform nondestructive testing (NDT) on welds as specified in AASHTO/AWS D 1.5
Bridge Welding Code and as following:
 Perform the NDT under the observation of the Engineer. Testers shall be certified
by the American Society for Nondestructive Testing (ASNT) at Level II or higher
and shall have at least two years of experience at that level.
 Submit a written report of all NDT to the Engineer along with material certification
documenting compliance of the welds with contract requirements.
a. Radiographic and Ultrasonic Inspection
Test groove welds in main members of built up girder structures by radiographic or
ultrasonic inspection as follows:
 Completely inspect tension splices and splices subject to reversals of stress;
 Test 1/6 of the web depth beginning at the point or points of maximum
tension and 25 percent of the remainder of the web depth on girder and beam
web splices; and
 Test all compression flange splices.
Test welds after grinding and retest repaired welds.
b. Magnetic Particle Inspection
Use the magnetic particle inspection method to test longitudinal beam or girder web
butt splices and fillet welds in main members, including the end connections, as
follows:



Test at random locations in the members so as to be typical for each size of
weld and type of joint;
Test 1 foot of every 10 foot length of weld; and
Test 1 foot of each weld less than 10 feet in length.
If defects are found in a test area, repair the full length of the weld or 5 feet on either
side of the test length, whichever is less.
Retest the repaired area plus at least 2 inches on each side of the repaired area.
F. Handling, Marking, Shipping, and Storing Materials
Mark each member with an erection mark for identification, and furnish an erection
diagram showing the erection marks.
Pack bolts of one length and diameter, and loose nuts and washers of each size
separately. Ship pins, small parts, small packages of bolts, washers, and nuts in suitable
containers with a list and description of the material plainly marked on the outside of
each container.
Load, transport, unload, and store structural material without stressing, deforming, or
damaging the structural members and so the metal is kept clean.
Handle long steel members by placing saddles at approximately the quarter points and
during storing and shipping placing blocking at intervals that prevent sag and distortion.
Store, ship and handle rolled beams and built-up plate girders in a vertical position.
Keep stored materials properly drained. Store steel above ground on platforms, skids or
other supports. Support girders, beams, and long members such as columns and chords
to prevent damage from deflection. Handle girder sections with beam clamps or other
approved devices and do not use wire rope slings.
Keep AASHTO 270 Grade 50W steel clean and free of materials that may affect the
metal’s natural oxidation. Provide temporary protection during concrete operations and
all operations that can affect uniform natural oxidation.
G. Falsework, Methods, and Equipment
Submit falsework plans to the Engineer. If changes in an existing structure are
necessary for maintaining traffic, submit plans to the Engineer for review.
H. Assembling Steel
Before assembly, clean bearing surfaces and surfaces that will be in permanent contact.
Assemble parts using the match marks. Bring splice points in beam or girder spans to
proper elevation and support them in position before the fasteners are tightened.
1. Bolts
Make permanent field connections using 7/8 inch diameter AASHTO M 164 highstrength bolts.
Make the diameter of the bolt holes 1/16 inch greater than the diameter of the bolts
used. Use bolts for transmitting shear that are threaded to a length that a maximum
of one thread is within the grip of the metal. Use bolts that are long enough to extend
entirely through the nuts but not more than 1/4 inch beyond the face of the nut. Place
one lock washer under the nut of each bolt connecting handrails. Install a hardened
washer over slotted holes.
Use galvanized nuts with a visible lubricant is on the threads.
Use black bolts and nuts that are oily to the touch when delivered and installed.
If bolts and nuts lose lubrication, clean and lubricate the bolts and nuts before
installation. Test recleaned or relubricated bolt, nut and washer assemblies as
specified in Section 616.04 H.2.a “Bolt-Nut-Washer Assembly Testing.”
2. Bolt Connections
Tighten high strength steel bolts using the following requirements:
a. Bolt-Nut-Washer Assembly Testing
Perform the rotational-capacity test specified in Section 834.03 B.2.d
“Assemblies” on each rotational-capacity lot before starting bolt installation. A
Skidmore-Wilhelm Calibrator tension measuring device will be provided by the
Engineer at each project site during erection. Use hardened steel washers for
tests.
If using the calibrated wrench method, perform the test each day that bolts are
installed. If using other methods, perform the tests on each production lot. The
Engineer will verify the installation test procedures.
Use direct tension indicators when testing bolts that are too short for the
Skidmore-Wilhelm Calibrator. Calibrate the direct tension indicators in the
Skidmore-Wilhelm Calibrator using longer bolts.
b. Installation Preparation and Tension requirements
Ensure bolted parts fit firmly together when assembled. Descale contact
surfaces, including washers, that carry more than normal tight mill scale. Contact
surfaces shall be free of defects that would prevent solid seating of the parts.
Install bolts with nuts on the interior side of the web and on the top side of the
flange.
Install bolts with a hardened washer under the bolt head or nut, whichever is
turned in tightening. Use a flat washer when the abutment surface adjacent to the
bolt head or nut does not have a slope of more than 1:20 with respect to a plane
normal to the bolt axis. Where an outer face of the bolted parts has a slope of
more than 1:20 with respect to a plane normal to the bolt axis, use a smooth
beveled washer to compensate for the lack of parallelism. Tighten all fasteners to
the minimum bolt tension values shown in Table 616-## “Required Fastener
Tension” on completion of the joint.
Table 616-##
Required Fastener Tension
Bolt Size
Minimum Bolt
(Inches)
Tension*
(Pounds)
1/2
12,000
5/8
19,000
3/4
28,000
7/8
39,000
1
51,000
1-1/8
56,000
1-1/4
71,000
1-3/8
85,000
1-1/2
103,000
*Equal to 70 percent of specified minimum tensile
strength of bolts as specified in ASTM Specifications for
tests of full size A-325 bolts with UNC threads loaded in
axial tension.
c. Installation Methods
Do not use high strength bolts that were previously tightened to requirements of
Table 616-##. Replace the assembly with a new bolt and nut. Replace the
assembly at no additional cost to the Department.
(1) Turn-of-Nut Tightening
Snug tighten all bolts in the joint with a few impacts of an impact wrench or the
full effort of a worker using an ordinary spud wrench. Ensure the parts of the joint
are in full contact with each other. Match mark the nuts and protruding bolt ends
before final tensioning so that the actual rotation can be determined.
Perform final tensioning by the applicable nut rotation specified in Table 616-##
with tightening progressing systematically from the rigid part of the joint to its free
edges. During this operation, do not allow rotation of the part not turned by the
wrench.
For bolts installed by 1/2 turn or less, rotate within a tolerance of plus or minus 30
degrees. For bolts installed by 2/3 turn or more, rotate within a tolerance of plus
or minus 45 degrees.
Table 612-## “Nut Rotation from Snug Tight Condition Disposition of Outer
Faces of Bolted Parts” applies only to connections in which all material within the
grip of the bolt is steel.
Table 612-##
Nut Rotation from Snug Tight Condition
Disposition of Outer Faces of Bolted Parts
One face normal to
Both faces sloped not
Bolt Length
Both faces
both axis and other
more than 1:20 from
(underside of head to
normal to
sloped not more than normal to the bolt axis
end of bolt)
bolt axis
1:20 (beveled washer
(beveled washers not
not used)
used)
4 Diameters and
1/3 turn
1/2 turn
2/3 turn
smaller
1/2 turn
2/3 turn
5/6 turn
Over 4 thru 8 Diameters
Over 8 thru 12
Diameters*
2/3 turn
5/6 turn
1 turn
*For bolt lengths exceeding 12 diameters, determine the required rotation by
actual test in a suitable tension measuring device which simulates conditions of
solidly fitted steel.
(2) Calibrated Wrench Tightening
Set calibrated wrenches to the minimum tensions required in Table 616-##
“Required Fastener Tension – Calibrated Wrench Tightening.”
Table 616-##
Required Fastener Tension – Calibrated Wrench Tightening
Bolt Size
Minimum Bolt
(Inches)
Tension*
(Pounds)
1/2
12,600
5/8
19,950
3/4
29,400
7/8
40,950
1
53,550
1-1/8
58,800
1-1/4
74,550
1-3/8
89,250
1-1/2
108,150
Calibration: Calibrate wrenches using the Skidmore-Wilhelm Calibrator.
Calibrate by tightening three typical bolts of each diameter, length and grade
from the bolts being installed. Use a hardened washer from the washers being
used in the work under the element turned in tightening.
Recalibration: Recalibrate wrenches when there is significant difference in the
surface condition of the bolts, threads, nuts, or washers.
Verification: Verify that the wrench adjustment selected by the calibration does
not produce a nut or bolt head rotation from snug tight greater than that permitted
in Table 2 during actual installation in the assembled steelwork. If manual torque
wrenches are used, measure torque when turning nuts in the tightening direction.
Installation: Install and tighten bolts in all holes of the connection to a snug tight
condition. Use hardened washers under the element turned. Following the initial
tightening operation, further tighten the connection using the calibrated wrench.
Tighten systematically from the most rigid part of the joint to its free edges.
Recheck: Recheck previously tightened bolts to ensure they have not relaxed as
a result of the subsequent tightening of adjacent bolts. Keep rechecking bolts
until all bolts are tightened to the specified minimum required tension.
.
(3) Direct Tension Indicator (DTI) Tightening
Use DTI’s that indicate the minimum tensions specified in Table 616-##. Follow
the manufacturer’s installation procedure for installation of bolts in the calibration
device and in all connections. Give special attention to proper installation of flat
hardened washers when using DTI with bolts installed in oversize or slotted holes
and when using the DTI under the turned element.
(a) Calibration Testing of DTI
Assemble a minimum of 3 DTI test assemblies for each length, diameter, and
grade of fastener. The test assemblies shall be identical to the assemblies
required in the connection. Test the assemblies in a calibration device capable of
indicating bolt tension.
(b) Installation
Install bolts in all holes of the connection and tighten to achieve partial
compression of the DTI protrusions. Tighten all fasteners, progressing
systematically from the most rigid part of the connection to the free edges in a
manner that will minimize relaxation of previously tightened fasteners. Proper
tensioning of the bolts may require more than a single cycle of systematic partial
tightening before final tightening to deform the DTI protrusions to the specified
gap.
(4) Alternate Design Fasteners (ADF)
Use alternate design fasteners (ADF) that meet the specifications in Section
834.03 B. Follow the manufacturer’s installation procedure for installation of bolts
in the calibration device and in all connections.
(a) Verification testing of ADF
Assemble a minimum of 3 ADF test assemblies for each length, diameter,
and grade of fastener to be used in the work. If required in the actual
connection, include flat-hardened washers in the test assembly arranged as
in the actual connections to be tensioned. Test the samples at the job site in
a device capable of indicating bolt tension. Only use ADF represented by
samples that develop a tension required by Table 616-3.
(b) Installation
When ADF are used, install bolts in all holes of the connection and initially
tighten them sufficiently to bring all plies of the joint into firm contact but
without yielding or fracturing the control or indicator element of the fasteners.
Then, further tighten all fasteners, progressing systematically from the most
rigid part of the connection to the free edges in a manner that will minimize
relaxation of previously tightened fasteners. Ensure proper tensioning of the
bolts by systematically partially tensioning them until final twist-off of the
control or indicator element of individual fasteners during the final tightening
cycle. Use more than a single cycle of systematic partial tightening. If twistoff occurs on an individual ADF prior to the final tightening cycle, replace the
fastener with a new one.
H. Straightening Steel Members
If members are bent, they must be replaced or returned to fabricator for repair. Do not
straighten bends in main structural members in the field.
Straighten bent members without producing embrittlement, fracture, or damage.
Straighten all material cold. Do not use members that cannot be straightened.
The Engineer may authorize heating mild steel and structural grade steel. Do not allow
the temperature of the heated area to exceed 1,200°F. (a dull red) as controlled by
temperature indicating crayons, liquids, or bimetal thermometers.
I. Field Painting
Perform field painting as specified in Section 630.
J. Rust Stains
When Weathering Steel is used protect substructure units with reinforced polyethylene
or similar material. Leave the protection material in place to prevent staining until the
superstructure is completed.
Use a concrete rust stain remover to remove all rust stains on the substructure units.
Flush all areas receiving applications of rust stain remover with water.
616.05 METHOD OF MEASUREMENT
The Engineer will measure as specified in Section 109.01 “Measurement of Quantities” and as
follows:
A. General
If the structural steel is measured by weight, furnish two copies of calculated weights
and dimensions.
B. Measurement by Weight
Measurement by weight will be by the Pound. The quantity paid for will be the total weight, determined as
specified.
The Engineer will measure and pay for all castings and miscellaneous metal parts as
Structural Steel. The Engineer will use the following pounds per cubic foot of metal as
the basis of computation:
Aluminum, Cast or Wrought
Brass
Bronze, Cast
Bronze, Wrought
Copper, Sheet
Iron, Cast
Iron, Malleable
Lead, Sheet and Plate
Steel
Zinc, Sheet
173.0
534.0
536.0
555.0
558.0
445.0
470.0
707.0
490.0
450.0
1. Structural Steel and Wrought Metals
The Engineer will not measure or pay for the weight of permanent bolts 6 inches or less
in length, The Engineer will not make deductions for cuts, copes, bevels, or open holes;
and will not make allowance for mill overruns.
2. Structural Plates
The Engineer will compute the weight of rectangular plates, such as web plates, cover
plates, batten plates, etc., on the basis of the net length and width shown on the Plans.
The Department will not make allowance for planed or sheared edges.
The Engineer will compute the weight of irregular shape on the basis of the dimensions
of the smallest rectangular plate from which it can be cut. When plates are machine
finished, the Engineer will consider the dimension of the plates the maximum machine
finished dimension plus 1/8 inch for each finished surface.
3. Structural Shapes and Bars
The Engineer will compute the weight of all bars and structural shapes with square ends
on the basis of the net section and the length as shown on the Plans.
The Engineer will compute the weight of each structural shape with mitered ends on the
basis of the section and overall length measured parallel to the axis of the shape.
For identical structural shapes with mitered ends that are less than 5 feet long, the
Engineer will consider ends multiple cut. The Engineer will compute their total weight as
the weight of the shortest parent section from which they can be cut, provided the length
of the parent section is not more than 30 feet.
4. Pins and Rollers
The Engineer will consider the parent section for forged segmental rollers square in
section, and of the same length, width, and thickness as the finished roller.
The Engineer will compute the weight of hot-rolled bar steel pins and rollers on the basis
of the length shown on the Plans and on the basis of a diameter 1/4 inch greater than
that of the finished pin or roller. The Engineer will compute the weight of cold finished
bar steel pins and rollers on the basis of the net length and diameter shown on the
Plans.
5. Bolts and Tie Rods
The Engineer will compute the weight of bolts over 6 inches long and tie rods including
necessary nuts and washers used for connecting structural steel parts from the nominal
weights as given the American Institute of Steel Construction.
6. Castings
The Engineer will compute the weight of each casting from the net dimensions shown on
the approved shop drawings, with an addition of 10 percent to compensate for fillets and
overruns. Where machine-finished surfaces are required, the Engineer will make an
allowance of 1/8 inch in thickness for each surface so finished. If cored holes are shown
on the Plans, the Engineer will make a deduction for the full size of the core.
7. Pipe
The Engineer will compute the weight from the dimensions shown on the Plans and the
nominal weights of the pipe and fittings.
8. Sheet Metal
The Engineer will compute the weight from the smallest rectangular area from which the
developed surface can be cut.
C. Lump Sum Basis
When the Engineer measures for Structural Steel on a “Lump Sum” basis, the "Lump Sum"
includes all Structural Steel required.
1. If any change in design is made which affects the weight of material furnished, the
Engineer will measure the additional Structural Steel in pounds.
616.06 BASIS OF PAYMENT
Pay Item
Structural Steel
Structural Steel
Pay Unit
POUND
LUMP SUM
For adjustments to structural steel as specified in Section 616.05 C, the Engineer will obtain the
unit price by dividing the lump sum bid for “Structural Steel” by the total estimated weight of
structural steel shown on the Plans. The Engineer will use the same calculated rate for
deductions from payments due to reduction in weight due to changes in design.
Such payment is full compensation for furnishing all materials, connection devices, swedge bolt,
equipment, labor, and incidentals to complete the work as specified.