[IFC Tunnel] Modelling of collections of e.g. bolts (design) vs individual bolts

In the design phase a "reinforcement instruction" may be constructed as in the attached images. (See also attached doc).
This is very similar to what is described in the issue about mapped zones (https://github.com/bSI-InfraRoom/IFC-Specification/issues/358).
What is described here is a "screen" with longitudinal and lateral (roof/wall) extensions with a couple of design parameters:
- Sprayed concrete thickness
- Bolt length
- Bolt spacing/pattern
- Reinforcement class

Compare this with the modelling of individual bolts in an as-built model.

Do we cover this in the current IFC Tunnel proposal or do we e.g. need an Entity for this "screen" to which the design properties may be assigned?

Se also issues:
#358 : Similar way of describing/mapping zonal features
#484 : Design vs as-built information for injection
#485 : general issue about design vs as-built properties

[Bolts design.docx](https://github.com/bSI-InfraRoom/IFC-Specification/files/10277765/Bolts.design.docx)

Review the attached Bolts design.docx and compare its reinforcement screen with the current IFC Tunnel proposal and issue #358 on mapped zones. Clarify whether existing IFC concepts cover design collections versus as-built individual bolts, or document the need and properties for a new entity. Done means an agreed modelling direction is recorded against this issue.

Written by the indexing model from the issue text.