Steel Tub Girder Code Check (AASHTO) [STG]

Steel Tub Girder Code Check (AASHTO) [STG]

General

Girder: Girder for code check

Station: Station along the PGL

Code Check Template: The code check template is utilized to extract global parameters, results from finite element analysis, and limit states employed in the design process.

Panel Type [InteriorPanel/EndPanel]: The terms "end panel" and "interior panel" are used to describe the sections of a steel girder plate that are positioned at the ends and interior sections of the girder, respectively, as depicted in the accompanying figure. The interior panels comprise the remaining segments of the girder that lie between the end panels.

Result Case To Find Points of Permanent Load Contraflexure: According to AASHTO 6.11.1.1, the effective span can be determined differently for simple spans and continuous spans. For continuous spans, the effective span length should be calculated based on the points of contraflexure of the major axis bending moment under permanent loads, or by considering both simple supports and points of contraflexure. Following this approach, it is necessary to specify the result extraction case that represents the permanent loads to identify the points of contraflexure and, subsequently, the effective spans. This parameter is used to define the result extraction case to be applied in calculations related to contraflexure.

Straight/Curved[Straight Bridge/Curved Bridge]: This parameter defines the bridge type.

Variable Depth Start or End Location [Yes/No]: Set to Yes only at stations where web depth variation occurs, as specified in AASHTO 6.10.1.4. When set to Yes, the checks for equations (D6.5.2-1), (D6.5.2-2), and (D6.5.2-3) in D6.5.2 – Web Local Yielding will be performed.

If this input enabled, and a web stiffener is present at the code check station, the D6.5.2 – Web Local Yielding check shall not be performed.

PDF Name (Export): This parameter allows the name of the code check document to be modified when saving it as a PDF. When renaming the file, special attention must be given to the text characters on the linked page, as certain characters may interfere with parametric equations and lead to unexpected results.

Reinforcement

Input Data Preference [Override Deck Rebar/Use Deck Rebar]: For deck rebar to be used in girder code checks, users are provided with two options. The code checks can either be conducted using the modeled deck rebar or with new rebar definitions.

If the input data preference is defined with the option 'Override Deck Rebar,' the parameters listed below can be used to define the rebars for code checks. Otherwise, if the input data preference is defined with the option 'Use Deck Rebar,' the parameters below will not be applicable.

Lumped Top Reinforcement Area within the Effective Width: This parameter can be used to specify the lumped reinforcement area within the effective width when overriding deck rebar.

Distance from the Centerline of Top Bars to the Top of the Deck: This parameter can be used to define the distance from the centerline of the top reinforcement bars to the top of the deck.

Lumped Bottom Reinforcement Area within the Effective Width: This parameter can be used to specify the lumped reinforcement area within the effective width for the bottom deck rebar.

Distance from the Centerline of Bottom Bars to the Bottom of the Deck: This parameter can be used to define the distance from the centerline of the bottom reinforcement bars to the bottom of the deck.

Deck Rebar Material: This parameter can be used to specify the material used for the deck rebars.

Concrete Creep Adjustment Factor: To incorporate the effects of concrete creep in stress calculations that involve the application of long-term loads to the composite section in regions of negative flexure, the area of the longitudinal reinforcement can be conservatively adjusted by dividing it by the "Concrete creep adjustment factor." The concrete is assumed to transfer the force from the longitudinal deck steel to the rest of the cross-section, with concrete creep acting to reduce that force over time. It is important to note that assuming a value greater than 1 is a conservative approach and is not mandated by the AASHTO LRFD BDS. As such, it is not recommended to use this assumption in normal design practice. When using the default value of 1, the reinforcement area will remain unaltered.

Overrides

Override Effective Deck Width[Yes/No]: The Override Effective Deck Width parameter provides the option to manually specify the effective deck width instead of relying on the automatically calculated value. When set to “YES,” it allows engineers to enter a user-defined deck width that may better represent the actual structural condition, such as when the composite action is partial or the geometry is irregular. When left as “NO,” the system computes the value automatically.

Effective Deck Width: The Effective Deck Width parameter defines the deck width used in composite section calculations when the override option is enabled. Computed Effective Deck Width (readonly): Parameter displays the effective deck width automatically determined by the software based on geometric inputs. This value represents the width of the deck slab acting compositely with the girder. Override Span Length: Parameter enables manual input of the span length for code check computations. By default, the span length is determined automatically from the geometric model using insertion points and support lines, but when this override is activated, the user can define an alternative length.

Span Length: Parameter allows the user to enter the desired span length in feet when the override option is active.

Computed Span Length (readonly): Parameter displays the system-calculated span length derived from the model geometry using insertion points and support lines. This field is read-only and provides a transparent reference for verifying the geometric span assumed in the design check.