Seismic spectra NTC 2018
Elastic and design response spectraDefines the seismic action of a site to Italian NTC 2018, from basic hazard to the design spectrum. Once the point is placed on the map, the app interpolates the ag, F0 and Tc* parameters from the four surrounding nodes of the reference grid and builds the spectra for every limit state; each plot carries a draggable point that reads the period T and returns the corresponding acceleration and displacement.
Features
- Site selection by municipality, address or WGS84 coordinates, with interactive map and reference-grid nodes
- ag, F0, Tc* parameters interpolated from the reference grid for the four limit states (SLO, SLD, SLV, SLC)
- Nominal life VN and usage class: reference period VR and return periods TR computed automatically
- Local seismic response: subsoil categories A–E with Ss and Cc, topographic categories T1–T4 with St
- Design spectrum with behaviour factor q, overlaid on the reference elastic spectrum in the same plot
- Horizontal and vertical components of the seismic action
- Elastic displacement spectrum with peak ground displacement dg, and ADRS representation with the period line
- Reduced spectrum for base-isolated structures (T ≥ 0.8·Tis) with effective damping ξeff and coefficient η
- Draggable point on the plots, synchronised across acceleration, displacement and ADRS spectra
- Numerical T–Sd tables for every limit state, copyable to the clipboard for spreadsheet use