> 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-deconstruction-cbg/box-girder-cbg.md).

# Box Girder \[CBG]

## Box Girder Construction

Removes a box girder from the analytical model at a given stage. The placement and stiffness-activation stages below mirror the ones used when the girder was constructed, so the removal is applied consistently to the lower box and the deck.

**Box Girder:** Select the box girder that is removed in this deconstruction stage.

**Lower Box Placement Stage:** Stage associated with placement of the lower box section.

**Deck Placement Stage:** Stage associated with placement of the deck (top slab).

**Lower Box Stiffness Activation Stage:** Stage at which the lower box section contributes stiffness to the analytical model.

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

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

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

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

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

**Girder Self Weight Factor:** Multiplier applied to the box girder's computed self-weight for this stage. Leave at 1.0 for no adjustment.


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