> 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/truss-bridge-workflow/construction-tb/superstructure-construction-tb/girder-floor-beam-bracing-construction-selected-tb.md).

# Girder/Floor Beam/Bracing Construction (Selected) \[TB]

This object erects the girders, floor beams, cross frames and lateral bracings picked in it, in one construction stage of the staged construction analysis. **Girder/Floor/Support Beam Construction (Complete)** erects every girder, floor beam, lateral bracing and cross frame of the bridge at once; with this object the stages can follow an erection sequence instead, for example the approach girders first and an arch span with its floor beams later. Each member picked here is added to the structure at the stage, and its self weight is applied.

{% hint style="info" %}
**What erects what**

* Erect each member in one construction object only: every erection applies its self weight again. Do not also erect the same members with **Girder/Floor/Support Beam Construction (Complete)**.
* A **Delta Frame Unit** picked under **Girders** is erected without its legs. Erect the legs with **Delta Frame Unit Construction**, with **Unit Parts** set to Legs. The unit reports an issue when two construction objects erect the same part of it.
* The bearings are erected with **Bearing Construction**, and the deck with **Deck Construction**.
  {% endhint %}

## Girder Construction

**Stage:** The construction stage in which the picked members are erected. A value is required.

**Girders:** The girders to erect at this stage, picked from the model. Each girder is erected with its finite element line, its links to the deck and its links to the supports.

**Floor Beams:** The floor beams to erect at this stage, picked from the model.

**Cross Frames / Bracings:** The cross frames and bracings to erect at this stage, picked from the model.

**Lateral Bracings:** The lateral bracings to erect at this stage, picked from the model, also a **Top Lateral Bracing** placed at the bottom of the girders.

**Girder Self Weight Factor:** Factor applied to the self weight of the erected girders. A value of `1.0` applies the full self weight; values greater than `1.0` scale it up and values less than `1.0` reduce it proportionally.

**Floor Beam Self Weight Factor:** Factor applied to the self weight of the erected floor beams, in the same way. Only editable when **Floor Beams** has an entry.

**Cross Frame / Bracing Self Weight Factor:** Factor applied to the self weight of the erected cross frames, bracings and lateral bracings, in the same way. Only editable when **Cross Frames / Bracings** or **Lateral Bracings** has an entry.

**Stiffness \[No/Yes]:** With **Yes** (the default), the erected members are added to the structure at this stage and carry load from then on. With **No**, only their weight is applied and they do not take part in the structure.


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