> 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/truss-construction-tb.md).

# Truss Construction \[TB]

The Truss Construction workflow item activates truss members in the staged construction model. Starting at the selected stage the truss members either all trusses on the bridge, or only a user-selected subset become structurally active, contribute stiffness, and carry their own self-weight.

## Truss Construction

**Stage:** Select the [Construction Stage \[TB\]](/templates/truss-bridge-workflow/construction-tb/construction-stage-tb.md) at which the truss members will be constructed. The truss FE group is activated from this stage onward.

**Bridge:** Select the [Bridge Alignment \[TB\]](/templates/truss-bridge-workflow/bridge-geometry-tb/bridge-alignment-tb.md) whose truss elements are being constructed. The truss FE group associated with that bridge is used when constructing all trusses.

**Construct All/Selection \[All/Selection]:** Choose whether to construct every truss on the bridge (**All**) or only a specific set of trusses (**Selection**). When **All** is selected the full truss FE group of the bridge is activated; when **Selection** is selected only the trusses listed below are activated.

**Selected Trusses:** Pick the individual trusses to be constructed at this stage. This list is only used when **Construct All/Selection** is set to **Selection**.

**Truss Self Weight Factor:** Factor applied to the truss members' own weight during this construction stage. A value of `1.0` applies the full self-weight; a value greater than `1.0` scales the self-weight up (e.g. to account for connection hardware or sacrificial elements), while a value less than `1.0` reduces it. The factor is applied as a downward (negative Z) body-force multiplier on the activated truss FE group.

**Stiffness \[No/Yes]:** Choose whether the truss members contribute stiffness to the FE model from this stage onward. In most construction scenarios this is set to **Yes** so that the trusses start resisting load at their construction stage; **No** can be used when the trusses are present but not yet structurally engaged (e.g. for weight-only staging).


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