> 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/examples/steel-bridge-examples/example-steel-tub-girder-bridge-ex1-stg/construction-ex1-stg/superstructure-construction-ex1-stg/superstructure-attachment-construction-ex1-stg.md).

# Superstructure Attachment Construction

This section defines the construction stage for superstructure attachments such as barriers.

{% hint style="info" %}
**Navigation:** Construction > Superstructure Construction > Superstructure Attachment Construction

For detailed parameter explanations, see the [Superstructure Attachment Construction Reference](https://docs.openbrim.org/templates/steel-tub-girder-bridge-workflow/construction-stg/superstructure-construction-stg/superstructure-attachment-construction-stg).
{% endhint %}

## Overview

Barriers in steel I-girder bridges are typically constructed after the deck pouring stages are completed. They are designed to provide a physical barrier between the roadway and any areas where vehicles or pedestrians should not be allowed.

Bridge owners usually prefer to be conservative and avoid using barrier stiffness in finite element analysis. To achieve this in OpenBrIM, the user can input a self-weight factor of 1 and select "No" for stiffness. However, this approach will not suffice if the user intends to apply wind loads to the structure, as OpenBrIM requires finite element representation of wind-exposed objects. In such cases, the user should select "Yes" for stiffness and assign materials with low E to decrease the barrier's stiffness.

### Barrier Construction Sequence

1. **Formwork installation:** Similar to deck pouring stages, formwork is used to shape and support the concrete barrier during the construction process
2. **Reinforcement installation:** Steel rebar is installed into the formwork to add strength to the barrier
3. **Concrete pouring:** Concrete is poured into the formwork, carefully placed and compacted to minimize voids
4. **Curing:** Concrete is left to cure and harden for several days
5. **Finishing:** Formwork is removed and surface is smoothed; protective coating may be applied

## Steps

### Step 1: Navigate to Superstructure Attachment Construction

Navigate to **Loading > Construction > Superstructure > Superstructure Attachment Construction** in the tree view.

![Attachment construction navigation](https://openbrim.atlassian.net/wiki/download/attachments/2168913945/image-20230223-082159.png?api=v2)

### Step 2: Select Construction Stage

Click the **three-dot icon** on the **Stage** cell and select **FBarrierStage** as the stage.

![Stage selection](https://openbrim.atlassian.net/wiki/download/attachments/2168913945/image-20230223-082240.png?api=v2)

### Step 3: Pick Barrier Objects

Click the **three-dot icon** on the **Barrier** cell and select **Pick**.

Pick the barrier objects from the 3D view, then click **Done** after selection is completed.

## Verification

{% hint style="success" %}
All barrier objects should be assigned to the FBarrierStage.
{% endhint %}


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