# Wedge Numbering

You will notice that **UnWedge** automatically assigns names and numbers to the wedges generated by the analysis. The wedge number is always displayed in square brackets after the wedge name (e.g., Roof Wedge [8]).

The wedge numbering convention is as described below.

## Perimeter Wedges

The Perimeter Wedges are numbered from 1 to 8. For the Perimeter Wedges, the wedge numbering corresponds to the **Joint Codes**, as follows:

Wedge # | Joint Code |

1 | 000 |

2 | 001 |

3 | 010 |

4 | 011 |

5 | 100 |

6 | 101 |

7 | 110 |

8 | 111 |

This means that a wedge number will always correspond to the same combination of halfspaces formed by the joint planes. For information about the Joint Codes see the Wedge Information topic.

If a wedge number is "missing", this means that the wedge corresponding to that Joint Code, cannot be formed. A maximum of six Perimeter Wedges can be formed for any Tunnel Axis Orientation, so there will always be at least two wedges which are not formed, and at least two wedge numbers will always be missing from the list of Perimeter Wedges.

The wedge numbering will correspond generally to the wedge naming. For example, for a horizontal tunnel, Wedge 1 will typically be the Floor Wedge (Joint Code = 000) and Wedge 8 will typically be the Roof Wedge (Joint Code = 111). Wedge numbers 2 to 7 will correspond approximately to other wedge names (e.g., Upper Left, Lower Right), however, this will depend on the Tunnel Axis Orientation and Joint Orientations so will vary depending on the model.

## End Wedges

The two End Wedges are always numbered 9 and 10, regardless of the numbering of the Perimeter Wedges, or how many Perimeter Wedges have actually been calculated by **UnWedge**.

In general, the End Wedge naming/numbering does *not* correspond to specific Joint Codes. The two End Wedges may correspond to any of the 8 Joint Codes listed above for Perimeter Wedges. This will depend on the Tunnel Axis Orientation and Joint Orientations.

However, the Near End Wedge is always number 9 and the Far End Wedge is number 10. For vertical or near-vertical excavations, the Roof Wedge is always number 9 and the Floor Wedge is number 10.