What do the Untergrundklassen R, S und T describe?
The Untergrundklassen are the geological subsoil classes of German seismic design under DIN EN 1998-1/NA: R for areas of rock-like ground, T for transition zones with shallower sediments, and S for regions of deep sedimentary basins. Together with the earthquake zone, the subsoil class parametrises the seismic action a structure must be designed for. Mapular provides these classes as queryable polygons, so both seismic parameters can be read for any site programmatically.
How binding are Untergrundklassen in seismic design?
Legal status
Reference data
An authoritative input for analysis and screening. It carries no legal effect of its own.
The geological subsoil classes R, S, and T are defined in DIN EN 1998-1/NA, the German national annex to Eurocode 8 for seismic design. The classification parametrises a binding design standard. This layer is reference data that makes it available as queryable geodata.
What this means for you
For your workflow, the subsoil class is the second seismic input alongside the earthquake zone: together they determine the response spectrum for the seismic verification. Having both as data means seismic screening covers the full parameter pair from the start. The binding verification remains the structural engineer's task.
Which attributes do the Untergrundklassen include?
- Subsoil class: The geological subsoil class R, S or T as defined in DIN EN 1998-1/NA: rock-like ground, deep sediment basins, or the transition between them.
- Zone geometry: The class boundary as a polygon, so any address or coordinate can be intersected and assigned to exactly one subsoil class.
- Federal state: The Bundesland each polygon belongs to, for filtering, state-level reporting, and portfolio breakdowns.
- Classification basis: A reference to the underlying standard, DIN EN 1998-1/NA, documenting which classification scheme the value follows.
The distribution of subsoil classes mirrors Germany's geology: rock-like ground (R) dominates the low mountain ranges, deep sedimentary basins (S) characterise regions such as the major river valleys and basins, and transition zones (T) lie between them. Because geology ignores state borders, most federal states contain more than one class.
What can you do with Untergrundklassen as Geodaten?
- Complete your seismic screening: pair each site's earthquake zone with its subsoil class to cover both parameters DIN EN 1998-1/NA requires.
- Feed early structural design assumptions in seismically relevant regions with a documented R/S/T class before ground investigations are commissioned.
- Automate due diligence for portfolios in the Rhine rift, Swabian Alb, and Vogtland belts, where zone and subsoil class together shape design effort.
- Standardise documentation: attach the same classified subsoil value to every feasibility report instead of transcribing it from maps by hand.
Where do the Untergrundklassen come from?
Standardised geological subsoil classifications from the German national annex to Eurocode 8, compiled into one consistent, queryable nationwide layer.
Which Bundesländer do the Untergrundklassen cover?
The Untergrundklassen layer covers all 16 German federal states, so the geological subsoil class can be queried for any site nationwide and combined directly with the earthquake zone of the same location.
Coverage by federal state
- BBBrandenburgAvailable
- BEBerlinAvailable
- BWBaden-WürttembergAvailable
- BYBavariaAvailable
- HBBremenAvailable
- HEHesseAvailable
- HHHamburgAvailable
- MVMecklenburg-Western PomeraniaAvailable
- NILower SaxonyAvailable
- NWNorth Rhine-WestphaliaAvailable
- RPRhineland-PalatinateAvailable
- SHSchleswig-HolsteinAvailable
- SLSaarlandAvailable
- SNSaxonyAvailable
- STSaxony-AnhaltAvailable
- THThuringiaAvailable
Where the federal state publishes this layer, we carry it: 16 of 16 federal states today. Where it doesn't, we say so.
Coverage gap
Your region of interest isn't covered?
Coverage follows what each state and municipality has actually digitised, so there are real gaps, and they are not always where you would expect. Tell us the region and the layer you need and we will look into what can be sourced for it, including data we do not list today.
Tell us what you needHow do you access the Untergrundklassen layer?
One unified dataset: Ready for direct integration into your GIS, CAD, or BI tools. Standard formats, documented schema.
Mapular Explorer: Instant planning interface, no GIS setup required. Filter, analyse, and export from your browser.
Frequently asked questions about Untergrundklassen
What are Untergrundklassen?
Untergrundklassen are the geological subsoil classes of German seismic design, defined in DIN EN 1998-1/NA, the national annex to Eurocode 8. Class R denotes areas of rock-like ground, class S deep sedimentary basins, and class T the transition between them. Together with the earthquake zone, the class parametrises the seismic action used in design.
What do the classes R, S, and T stand for?
In DIN EN 1998-1/NA, subsoil class R stands for regions of rock-like ground, class S for regions of deep sedimentary basins, and class T for transition zones with shallower sediment cover. The classification captures, at a regional geological scale, how the ground influences seismic ground motion at a site.
How are Untergrundklassen used together with Erdbebenzonen?
German seismic design under DIN EN 1998-1/NA needs both parameters: the earthquake zone scales the seismic action, and the geological subsoil class (R, S, or T) shapes the response spectrum through which that action is applied to the structure. A complete seismic screening of a site therefore always reads zone and subsoil class together.
Does the Untergrundklassen layer replace a geotechnical or structural investigation?
No. The layer provides the standardised regional subsoil class as reference data, which makes seismic screening and early design assumptions fast and consistent. Site-specific ground conditions and the binding seismic verification must still be established by qualified geotechnical and structural engineers under the applicable standards.
Why query Untergrundklassen as geodata instead of reading maps?
As geodata, the subsoil classes become a per-site attribute: intersect a coordinate with the polygons and receive R, S or T. Combined with the earthquake zone from the sibling layer, this turns seismic pre-assessment into an automated query across entire portfolios, instead of a manual map lookup for every single site.
Which parts of Germany does the Untergrundklassen layer cover?
Mapular's Untergrundklassen layer covers all 16 German federal states in one consistent dataset. Every location in Germany can be assigned its geological subsoil class R, S, or T, and the value can be combined directly with the earthquake zone of the same site for seismic screening.