Design Concept
The design of reinforced concrete structures in seismic situations for earthquake zones can be divided into the following steps. [1]
1 - Determination of design parameters
2 - Selecting a structural system
3 - Structural design
4 - Seismic analysis
5 - Ultimate limit state design
6 - Capacity design
Ductility Classes
In order to withstand earthquakes, it is necessary to design structures according to Eurocode 8 for either low dissipative energy dissipation capacity or sufficient energy dissipation capacity.
There are two levels of seismic design that can be applied optionally:
- Ductility class medium (DCM) - This requires the use of low behavior factors and allows lower requirements for the deformation capacity (ductility) of the structural components.
- Ductility class high (DCH) - Higher behavior factors may be used for this class. However, the requirements for the deformation capacity of the structural components are correspondingly high.
For concrete structures, seismic design according to the ductility class low (DCL) is also allowable as an alternative, in which case the design is carried out solely in accordance with EC 2. However, this is only recommended for low seismicity.
Dimensioning of Concrete Components
The following sub-chapters describe the dimensioning of specific components for seismic conditions.