Expert/source verification requiredEdition-dependent or normative details must be confirmed against the adopted standard and National Annex before project use.
Ground classificationSite amplificationGeotechnical investigationEN 1997 relationship
Learning objectives
In this lesson
- Ground classification must be evidence-based.
- Site effects change period-dependent demand.
Engineering explanation
Soil stiffness, stratigraphy and depth can alter amplification and frequency content. Ground classification is therefore a model input linking field investigation to structural demand, not an administrative label. For the same reference hazard, a stiff site and a deeper softer deposit can produce different spectrum shapes around a building period. A valid comparison uses verified profiles and applicable spectrum rules, not a generic multiplier. EN 1997 investigation evidence and EN 1998 seismic inputs must be coordinated.
Key takeaways
What to carry forward
- Ground classification must be evidence-based.
- Site effects change period-dependent demand.
- Coordinate geotechnical and structural inputs.