> 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/bebo-precast-arch-bridge-workflow/precast-concrete-arch-bebo.md).

# Precast Concrete Arch \[BEBO]

The Precast Concrete Arch is the primary object of this template. It generates the precast arch units spanning between the selected stem walls or abutments, from the arch geometry and thickness given here.

## General

**Stem Walls/Abutments:** The stem walls or abutments the arch springs from. The arch legs are seated on the selected supports.

**Arch Type \[Circular=0/Ellipse=1]:** Shape of the arch curve — a circular segment or an ellipse (default: Ellipse=1).

**Rise:** Height of the arch measured from the springing line to the crown (default: 288).

**Thickness:** Thickness of the precast arch shell (default: 12).

**Width Option\[Match Stem Wall Width=0/Input=1]:** Chooses whether the arch width follows the supporting stem walls or is entered directly below (default: Input=1).

**Width:** Width of the arch along the structure. Applicable when Width Option is Input.

**Transverse Offset:** Transverse offset of the arch from the alignment (default: 0).

**Downstation Leg Offset Along PGL:** Longitudinal offset of the down-station arch leg, measured along the PGL (default: 0).

**Upstation Leg Offset Along PGL:** Longitudinal offset of the up-station arch leg, measured along the PGL (default: 0).

**Crown Width:** Width of the flat portion at the crown of the arch. Enter 0 for a continuously curved crown (default: 0).

**Material:** Concrete material assigned to the precast arch units.

## 3D Settings

**Arch Refinement:** Number of segments the arch curve is drawn with in the 3D view. Higher values look smoother (default: 40).

## Quantities

**Span Length:** Clear span of the arch between its supports. (Read-only)

**Development Length:** Developed length of the arch curve from springing to springing. (Read-only)

**Volume:** Concrete volume of the arch. (Read-only)

**Weight:** Concrete weight of the arch. (Read-only)


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