This is the dialog where you define the mounting bolt groups in your tunnel.

First, you must specify the name and the chainage interval for the bolt group. The bolts you specify in this dialog will be placed regularly from the first chainage value to the last stationing/chainage value with steps equal to the Interval value.

The name is just for making it easy to recognize the bolt group specification later.

Localization Defined By

There are several possible methods to define the bolt group center axis:

For each of these methods, you can specify an offset or angle from the reference axis to the bolt group center axis.

The point where the bolt center axis intersects with the inner profile is the bolt group origo.

Bolt Direction

The bolt direction can be defined as:

The bolt direction is set up from the bolt group origo and defines the bolt group system axis

Bolt Lengths

The bolt length is defined as the distance from either the inner surface or the perimeter to the rock end or to the free end of the bolt. The final location of the bolt is then decided by following the bolt direction from the bolt group origo until it intersects with the surfaces specified for the bolt lengths and then setting the bolt ends at the correct distances from these surfaces.


Several bolts can be defined for the same bolt group. All the bolts are parallel and have an equal length. They are placed with the user-specified transverse offset A normal to the bolt group system axis in the cross-section plane and the longitudinal offset B normal to the bolt group system axis in the longitudinal direction.