> 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/construction-cbg/superstructure-construction-cbg/box-girder-cbg.md).

# Box Girder \[CBG]

## Box Girder Construction

**Box Girder:** Select the box girder that is placed in this construction stage.

**Lower Box Placement Stage:** Stage at which the lower box section is placed. Its self-weight is applied to the structure from this stage onward.

**Deck Placement Stage:** Stage at which the deck (top slab) is placed. Its self-weight is applied to the structure from this stage onward.

**Lower Box Stiffness Activation Stage:** Stage at which the lower box section starts contributing stiffness to the analytical model. This is normally at or after the Lower Box Placement Stage, so freshly placed concrete carries load without adding stiffness.

**Deck Stiffness Activation Stage:** Stage at which the deck starts contributing stiffness to the analytical model.

**Start Station:** Station along the PGL at which the constructed portion of the girder begins.

**End Station:** Station along the PGL at which the constructed portion of the girder ends.

**Start Skew:** Skew angle applied to the start face of the constructed portion.

**End Skew:** Skew angle applied to the end face of the constructed portion.

**Girder Self Weight Factor:** Multiplier applied to the box girder's computed self-weight when the girder is activated in this construction stage. Use values greater than 1.0 to account for appurtenances not modeled explicitly; leave at 1.0 for no adjustment.


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