The wikipedia page for groundworks (earthworks) does mention contour trenching and cut & fill but not a word about bring tunnels. Is a bored tunnel part of groundworks discipline/field? If not what discipline does it belong to.
In my experience groundworks refers to the site activity of shallow work in the ground, such as trenches (for foundations or drainage) and slab foundations.
Tunnel construction comes under the term tunnelling. Tunnelling is a specialist activity: you wouldn't want a general groundworks contractor to try boring tunnels, and you wouldn't want a tunnelling contractor to dig shallow foundations.
On the design side they are all part of the discipline of geotechnical engineering. Again, tunnelling is specialised on the design side too, and will be done be specialised geotechnical engineers. Foundation design may be carried out by structural engineers or geotechnical engineers, mainly depending on how complicated it is. Small residential building foundations are designed by rules of thumb based on the soil type; skyscraper foundations take much bigger loads and rules of thumb are not sufficient.
It's surprisingly difficult to find a definition for Groundworks.
There are plenty for "groundwork" as:
the foundation, basis, preliminary or basic works
Much of the usage of "groundwork" seems to be metaphorical, comparing "preliminary work" for any type of project to laying the foundation for constructing a building.
Wikipedia does have a page for "groundworker" as somebody who:
clears the site, lays a foundation, installs drainage and other pipework, and may build roads if necessary
A typical website for a "groundworks" contractor talks about:
- Re-profiling the earthworks to required design levels
- Drainage and roads
- Foundations and buildings
- Ground floor slab
- SurfacingFinishing touches
This seems consistent with the definition for "groundworker" - someone who does shallow depth work in the ground, typically for buildings.
Geotechnical engineering is defined as:
Geotechnical engineering is the branch of engineering concerned with the analysis, design and construction of foundations, slopes, retaining structures, embankments, tunnels, levees, wharves, landfills and other systems that are made of or are supported by soil or rock.