This International Standard provides guidelines for specifying seismic actions for designing geotechnical works, including buried structures (e.g. buried tunnels, box culverts, pipelines and underground storage facilities), foundations (e.g. shallow and deep foundations, and underground diaphragm walls), retaining walls (e.g. soil retaining and quay walls), pile-supported wharves and piers, earth structures (e.g. earth and rockfill dams and embankments), gravity dams, landfill and waste sites. NOTE The guidelines provided in this International Standard are general enough to be applicable for both new and existing geotechnical works. However, for use in practice, procedures more specific to existing geotechnical works can be needed, such as those described for existing structures in ISO 13822.