Check the exterior girder for constructibility during the non-composite stage of construction.
Special Unit Definitions:
No holes in the beam.
Girder flanges are discretely braced.
Cb equal 1.0
No Longitudinal Stiffeners
Deck Thickness:
Deck Thickness at Edge of Deck:
Haunch (Bottom of Deck To Top of Web):
Deck Effective Width:
Overhang:
Width of the Compression Flange:
Thickness of the Compression Flange:
Width of the Tension Flange:
Thickness of the Tension Flange:
Web Depth:
Web Thickness:
Compression Flange Yield Strength:
Tension Flange Yield Strength:
Web Yield Strength:
Steel Modulus of Elasticity:
Hybrid Factor:
Unbraced Length:
Moment of Inertia (non-composite):
Distance N.A. to Extreme Fiber of the Bot. Flange (non-composite):
Depth of Web in Compression at Non-Composite Stage:
Span Length:
Bending Moment Due To All Non-Composite Dead Loads:
Bending Moment Due To Girder Weight:
Primary Bending Moments Due To Construction Loads:
Construction Dead Load M
Construction Live Load Mom
Wind Pressure on Structure (Article 3.8.1):
Load Modifier Relating to Ductility, Redundancy and Operational Importance:
The primary bending moments due to non-composite dead load (slab and girder weight) is typically computed assuming that the deck is placed on the entire bridge at the same time. Depending on the pour sequence specified by the engineer and the span configuration, the maximum non-composite dead load moment may be greater when considering the pour sequence.
Maximum dead load moment due to all non-composite dead loads input by the user:
Maximum moment due to girder weight input by the user:
In addition to the non-composite forces from the slab and girder dead load, IaDOT policy also requires that the following construction loads be applied to the non-composite stage of an exterior girder:
Dead Load Due To Deck Forms = 10 psf
Dead Load Rail Loading = 75 plf
Live Load Due To Finishing Machine = 6000 lb
These construction loads contribute to the primary bending moments and also the lateral bending moments due to the overhang forming brackets. A later section will compute the lateral bending forces from these loads.
Construction dead load moment due to form load and rail load input by the user:
Construction live load moment due to finishing machine input by the user:
Wind forces are considered
The base wind pressure of
Wind forces for this bridge, which is less than 30 feet above ground:
(but not less than 0.30 klf on structure)
Wind on Non-Composite
each flange
each flange
Calculate lateral loads due to deck cantilever weight, finishing machine and the forms.
IaDOT policy is to design for the following Construction Loads:
Form Loads = 10 psf
Finishing Machine = 6000 lb point load at edge of deck.
Rail and walkway load = 75 plf at edge of deck
Assume 1/2 the deck overhang weight is carried by the bracket at the bracket end.
Horizontal slab force:
Horizontal finishing machine force:
Horizontal rail plus form force:
If the unbraced length exceeds the first order maximum unbraced length (Eq. 6.10.1.6-2), then the lateral moment in the compression
Check the unbraced length as follows:
Radius of Gyration:
Limiting unbraced length to achieve nominal flexural resistance under uniform bending:
The largest value of the factored compressive stress throughout the unbraced length, f
Calculate the allowable unbraced length.
Determine if lateral moment magnification is required and the magnitude:
Calculate the magnified lateral flange moments for the slab and construction loads assuming the flange as a continuous beam and magnify if required.
Uniform Loads:
(C6.10.3.4-2)
Concentrated Loads:
(C6.10.3.4-3)
Slab Moment:
Construction lateral flange moment:
Calculate the factored moments for the various strength limit states considering loads applicable to a tangent bridge.
The constructibility checks are specified in Article 6.10.3.
where:
f
f
Note that Equation 1 need not be checked when the web is slender and the lateral stress equals zero and Equation 3 need not be checked when the web is compact or non-compact.
Determine if the web is classified as non-compact or slender.
(6.10.6.2.3-1)
Calculate the nominal flexural resistance of the compression flange so that Equation 2 above can be checked.
In determining the moment gradient modifier (C
Compression Flange Slenderness Ratio:
Limiting Slenderness Ratio for a Compact Flange:
Limiting Slenderness Ratio for a Noncompact Flange:
Calculate Nominal Capacity:
Flange Local Buckling For Non-Compact Flange
Determine Flange Compactness
Calculate required variables for resistance equations:
Radius of Gyration:
Limiting unbraced length to achieve nominal flexural resistance under uniform bending:
Limiting unbraced length to achieve nominal yielding in either flange:
Calculate nominal capacity for compact, non-compact and slender unbraced lengths:
Compact Unbraced Length
Non-Compact Unbraced Length
Slender Unbraced Length
Determine Lateral Torsional Capacity based on L
Calculate the web bend buckling resistance of the compression flange so that Equation 6.10.3.2.1-3 can be checked.
Check F
Check the three equations in Article 6.10.3.2 for Limit State I.
Primary Bending:
Lateral Bending:
Check to make sure the lateral bending stress is less than 0.6F
Performance ratio:
Check Equation 6.10.3.2.1-1:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.1-2:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.1-3:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.2-1 for Limit State I.
Primary Bending:
Lateral Bending:
Check to make sure the lateral bending stress is less than 0.6F
Performance ratio:
Check Equation 6.10.3.2.2-1:
Magnification factor is not applicable to the tension flange, therefore, it is removed below.
Left side of equation:
Right side of equation:
Performance ratio:
Check the three equations in Article 6.10.3.2 for Limit State III.
Primary Bending:
Lateral Bending:
Check to make sure the lateral bending stress is less than 0.6F
Performance ratio:
Check Equation 6.10.3.2.1-1:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.1-2:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.1-3:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.2-1 for Limit State III.
Primary Bending:
Lateral Bending:
Check to make sure the lateral bending stress is less than 0.6F
Performance ratio:
Check Equation 6.10.3.2.2-1:
Left side of equation:
Right side of equation:
Performance ratio:
Check the three equations in Article 6.10.3.2 for Limit State IV.
Primary Bending:
Lateral Bending:
Check to make sure the lateral bending stress is less than 0.6F
Performance ratio:
Check Equation 6.10.3.2.1-1:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.1-2:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.1-3:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.2-1 for Limit State IV.
Primary Bending:
Lateral Bending:
Check to make sure the lateral bending stress is less than 0.6F
Performance ratio:
Check Equation 6.10.3.2.2-1:
Left side of equation:
Right side of equation:
Performance ratio:
Check the three equations in Article 6.10.3.2 for Li
Primary Bending:
Lateral Bending:
Check to make sure the lateral bending stress is less than 0.6F
Performance ratio:
Check Equation 6.10.3.2.1-1:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.1-2:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.1-3:
Left side of equation:
Right side of equation:
Performance ratio:
Check Equation 6.10.3.2.2-1 f
Primary Bending:
Lateral Bending:
Check to make sure the lateral bending stress is less than 0.6F
Performance ratio:
Check Equation 6.10.3.2.2-1:
Left side of equation:
Right side of equation:
Performance ratio:
6.10.1.6-1
6.10.3.2.1-1
6.10.3.2.1-2
6.10.3.2.1-3
6.10.1.6-1
6.10.3.2.1-1
6.10.3.2.1-2
6.10.3.2.1-3
6.10.1.6-1
6.10.3.2.1-1
6.10.3.2.1-2
6.10.3.2.1-3
6.10.1.6-1
6.10.3.2.1-1
6.10.3.2.1-2
6.10.3.2.1-3
6.10.1.6-1
6.10.3.2.2-1
6.10.1.6-1
6.10.3.2.2-1
6.10.1.6-1
6.10.3.2.2-1
6.10.1.6-1
6.10.3.2.2-1