# 6. Substructure

This section covers the substructure components that support the bridge superstructure, including piers, foundations, and piles.

{% hint style="info" %}
Substructure elements are essential for load transfer from the superstructure to the ground. Each component must be properly dimensioned for the design loads.
{% endhint %}

## Components to Model

| Component                                                                                                                                            | Description                                   |
| ---------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------- |
| [Pier](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-i-girder-bridge-ex1-sig/substructure-ex1-sig/pier-ex1-sig)             | Pier caps and columns supporting the bearings |
| [Foundation](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-i-girder-bridge-ex1-sig/substructure-ex1-sig/foundation-ex1-sig) | Rectangular footings for load distribution    |
| [Pile](https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-i-girder-bridge-ex1-sig/substructure-ex1-sig/pile-ex1-sig)             | Deep foundation elements beneath footings     |

## Substructure Elements

* **Pier Caps**: Horizontal members that distribute loads from bearings to columns
* **Pier Columns**: Vertical members transferring loads from caps to foundations
* **Rectangular Footings**: Spread footings for foundation support
* **Piles**: Deep foundation elements for load transfer to bearing strata

## Model Views

![Pier Cap](https://openbrim.atlassian.net/wiki/download/attachments/2101903451/image-20250117-141559.png?api=v2)

![Pier Column](https://openbrim.atlassian.net/wiki/download/attachments/2101903451/image-20250117-141720.png?api=v2)

![Foundation](https://openbrim.atlassian.net/wiki/download/attachments/2101903451/image-20250117-141829.png?api=v2)

![Complete Substructure](https://openbrim.atlassian.net/wiki/download/attachments/2101903451/image-20250117-141927.png?api=v2)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.openbrim.org/examples/steel-bridge-examples/example-steel-i-girder-bridge-ex1-sig/substructure-ex1-sig.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.