> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/templates/concrete-box-girder-bridge-workflow/superstructure-code-checks-cbg/concrete-box-girder-code-check-cbg.md). # Concrete Box Girder Code Check \[CBG] This object runs the AASHTO code check at one station of a concrete segmental / box girder. Each instance pairs a girder (or segment) with a Concrete Segmental Girder Code Check Template and a control station; assumptions, factors and loss methods come from the template, while the per-station inputs (which stages to check, shear stirrup data, anchorage data, optional overrides) are supplied here. Place one of these at every section that needs to be checked; reuse the same template across them so global settings stay in one place. ### General **Code Check Template:** Pick the Concrete Box Girder Code Check Template that supplies the AASHTO factors, loss methods and section-analysis settings. Required. **Girder:** Pick the girder (or segment) being checked. The girder provides the section, materials, tendon list and shear-reinforcement layout used at the control station. Required. **Design Section w Rebars(or Tendons) \[Override Section/Section from 3D]:** How the design section is built at the control station. Section from 3D extracts the section directly from the girder's 3D geometry, including rebar and tendons. Override Section uses an explicit Section object provided below — use this when the section, rebar or tendon arrangement at this check point differs from what the 3D model carries. **Override Design Section:** Pick the Section object used as the design section. Required and visible only when Design Section is set to Override Section. **Stages for PS Stress Checks:** Construction stages at which the pretensioning (PS) service stress checks are evaluated. Each row pairs a stage with the AASHTO concrete stress limits to be enforced at that stage; populate it from the construction stages already defined on the project. **Stages for PT Stress Checks:** Construction stages and tendon-condition entries at which the post-tensioning (PT) service stress checks are evaluated. Each row pairs a stage with a tendon condition (Prior to seating, At anchorages after set, Elsewhere after set, At service after losses) and the AASHTO concrete stress limits to enforce. In Refined PT loss mode the first row must be a stressing entry (not At service after losses) and only one stressing event is allowed; in FEA Results mode any combination is permitted. **Code Check Distance from Start \[Start/End]:** Where along the girder the section is cut for the check. Enter `Start` or `End` to cut at the girder's start or end station, or a numeric distance from the girder start. Required. The exact endpoints are nudged inward by a small amount internally so the section evaluator does not land on a boundary node. **Relative Position (readonly):** Relative position along the girder, expressed as a station fraction with an `L` suffix. (Read-only) **PDF Name (Export):** Filename used when the per-station code check report is exported to PDF. **Girder/Segment Start Station (readonly):** Start station of the girder or segment being checked, shown for orientation. (Read-only) ### Shear Reinforcements **Shear Reinforcement Data \[Override Rebar Data/Use Girder's Rebar Data]:** Source of the transverse (stirrup) reinforcement data used in the shear check. Use Girder's Rebar Data reads the stirrup profile, spacing and material from the girder's Shear Reinforcement Data table at the control station; Override Rebar Data lets you supply the values explicitly below. If Use Girder's Rebar Data is selected, the girder's Shear Reinforcement Data must cover this control station — otherwise the shear capacity goes undefined. **Rebar Profile:** Pick the stirrup rebar product (size/grade) that resists shear at the control station. Required and visible only when Override Rebar Data is selected. **Rebar Spacing:** Center-to-center spacing of the stirrups along the alignment. Required and visible only when Override Rebar Data is selected. **Number of Legs:** Number of vertical stirrup legs crossing the shear plane in the section. Required and visible only when Override Rebar Data is selected. **Transverse Rebar Material:** Material of the transverse stirrup. Required and visible only when Override Rebar Data is selected. ### Overrides-Readonly **Override Effective Web Width (Shear bv) \[Yes/No]:** Whether the effective web width b\_v used by the shear check is overridden manually. With No the value is taken from the girder geometry at the control station; with Yes you supply a value below. **Effective Web Width (Override):** Effective web width b\_v supplied by the user. Visible only when the override above is set to Yes. **Computed Effective Web Width (readonly):** Effective web width b\_v computed from the girder's section geometry at the control station, shown for reference. (Read-only) Visible only when the override is set to No. ### Anchorage Zone **Is this station at a tendon anchorage? \[No/Yes]:** Whether the control station lies in a post-tensioning anchorage zone (per AASHTO 5.9.4.4). The default is auto-detected from the physical start/end stations of the girder's tendons, but you can force Yes or No here. The remaining inputs in this group become required only when this is Yes. **Anchor plate width:** Width *a* of the anchor plate at the anchorage being checked. Visible only when the station is at an anchorage. **Anchor eccentricity from section centroid (positive if below):** Eccentricity *e* of the anchor from the section centroid, positive when the anchor sits below the centroid. Visible only when the station is at an anchorage. **Tendon angle at anchorage (rad):** Angle α of the tendon path with respect to the section axis at the anchorage. Visible only when the station is at an anchorage. **Provided bursting reinforcement area at anchorage:** Area A\_s,burst of the bursting reinforcement actually provided at the anchorage, used to compare against the AASHTO 5.9.4.4 demand. Visible only when the station is at an anchorage. --- # Agent Instructions This documentation is published with GitBook. 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