and choose the Bent 1, Bent 2, or Bent 3 option to continue the model building process.Use the three forms to describe the geometry and stiffness properties for each span.
TIP: After specifying the span data, click the Define menu > Bents command or the Define Bents button and choose the Bent 1, Bent 2, or Bent 3 option to continue the model building process.
Deck Span Data 1 parameters.
Span No. This is the program assigned ID for the span.
Span Length column. Specify the span lengths (ft.) along the centerline of the bridge.
Moment of Inertia (lz, ly, lx) columns. Specify the moment of inertia (ft.4) of the superstructure for span 1 using this form, or the program will calculate it from the data specified on the Deck Span Data 2 form. The term 'normal bending' is used to denote bending caused by vertical loads. For spans higher than 1, if no value is given, the program will assume the value from the previous span. Changes in moment of inertia may be designated by providing a new moment of inertia.
X-Sectional Area column. The cross sectional area (ft.2) of the superstructure must be given for span 1 either in this form or be calculated by the program from the data in the Deck Span Data 2 form. This area is used to compute the superstructure weights. For spans higher than 1, if no value is given, the program will assume the value from the previous span. Changes in cross sectional area may be designated by providing a new cross sectional area.
Modulus E column. If this field is left blank, a modulus of elasticity of 468,000 ksf for concrete is assumed for the superstructure.
Structure Depth column. Enter the superstructure depth of the bridge. The structure depth is used for wind on live load, longitudinal force, centrifugal force, and column end joint size. If zero structure depth is given, the moments generated by these forces are applied at 6 feet above the bridge deck. If a structure depth other than zero is given, the generated moments are applied a distance (6' + 1/2 structure depth) above the C.G. of the structure, and the columns will have an end joint size of 1/2 the superstructure depth at the top. Apply the moments created by wind on LL, longitudinal force, and centrifugal force about any preferred axis by modifying the structure depth accordingly. If a structure has more than one depth entered, the structure depth used at the column will be the larger depth of the two adjacent spans.
Addl. Mass on SS column. Enter any masses that might add to the superstructure weight in addition to the cross section of the structure. This includes future wearing surface, barrier rail, and sidewalk.
If the superstructure section properties are entered in the Deck Span Data 1 form, no additional data is needed for this form. Otherwise, enter data on this form to calculate the superstructure properties.
Span No This is the program assigned ID for the span.
Super-Structure Width column. Enter the superstructure width from edge to edge. If the superstructure width and structure depth on the Deck Span Data 1 form are missing, no superstructure section properties will be calculated.
Slab Data
Top Slab Thickness column. Enter the thickness of the top slab.
Bot Slab Thickness column. Enter the thickness of the bottom slab. Enter 0 if defining a T girder.
Interior Girders
No of Interior Girders column. Enter the number of interior girders. Enter 0 for single cell box girder.
Interior Girder Web Width column. Enter the web width for interior girders only.
Exterior Girder
Left/Right Ext. Girder Type columns. Enter exterior girder type, 0 for vertical girder, 1 for sloped girder, 2 for sloped girder with 45 degree outside slope, 3 for rounded girder.
Left/Right Ext. Girder Web Width columns. Enter the exterior girder web width.
Left/Right Ext. Girder Factor columns. Enter the horizontal distance from the end of the overhang to the beginning of bottom slab.
Overhang
Left/Right Overhang Length columns. Enter the horizontal distance from the edge of the deck to the end of the overhang.
Left/Right Overhang Exterior Thickness columns. Enter the overhang thickness at the edge of the deck.
Left/Right Overhang Interior Thickness column. Enter the overhang thickness at the end of the overhang.
The geometry and stiffness properties for hinges and restrainers, wind load, wind on live load, and live load longitudinal force are described using this form.
Span ID. This is the program assigned ID for the span.
Hinge
Hinge Location column. The presence of a hinge is indicated by the distance (ft.) measured from the left end of the span. The hinge must be within the span and cannot be located at the left end of the span since a zero entry would be interpreted as no hinge. Only one hinge per span is possible and no hinges are permitted within the abutment half of the end spans.
Hinge X-Section Area column. Specify the total cross sectional area of the hinge diaphragm in square feet.
Hinge Overall Length column. The hinge length in feet is measured along the centerline of the hinge in the transverse direction of the bridge, along the hinge diaphragm.
Restrainer
Restrainer Length column. The user may specify the restrainer length in feet. If the length is left blank, a length of 20 feet is assumed for the default value
Restrainer Area column. The user must specify the cross sectional area of the restrainers in square inches. If the area is left blank or zero, no restrainer will be generated.
Restrainer Modulus - E column. A default value of 1,440,000 ksf (i.e., 10,000,000 psi for a steel cable) is assumed unless a value has been input, in which case the input value will override the default value.
Wind Load on SS column. Specify the wind intensity on the superstructure/bridge (kips/feet).
Wind Load on LL column. Specify the wind intensity on the live load (kips/feet).
Longitudinal Force column. Specify the longitudinal force caused by the live load (kips/feet).
See Also
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Access the Deck Span Data 1, Deck Span Data 2, or Deck Span Data 3 forms as follows:
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and choose