This lecture presents the topics covered by Part 1–Sections 1 & 2 and Part 5 of Eurocode 8 namely: seismic action, ground conditions and soil investigations, importance categories, importance factors and geotechnical categories. Also topics related with foundations behaviour under seismic loads, potentially liquefiable soils, foundation system and topographic aspects are discussed.
The Commission of the European Communities (CEC) initiated a work in 1975 of establishing a set of harmonised technical rules for the structural and geotechnical design of buildings and civil engineers works based on article 95 of the Treaty. In a first stage would serve as alternative to the national rules applied in the various Member States and in a final stage will replace them. From 1975 to 1989 the Commission with the help of a Steering Committee with the Representatives of Member States developed the Eurocodes programme. The Commission, the Member states of the EU (European Union) and EFTA(European Free Trade Association) decided in 1989 based on an agreement between the Commission and CEN (European Committee for Standardization) to transfer the preparation and the publication of the Eurocodes to CEN. The work performed by the Commission of the European Communities (CEC) in preparing the "Structural Eurocodes" in order to establish a set of harmonised technical rules is impressive. Nevertheless, due the preparation of these documents by several experts, some provisions of EC8 with the special requirements for seismic geotechnical design that deserve more consideration will be presented in order to clarify several questions that still remain without answer. The actual tendency is to prepare unified codes for different regions but keeping the freedom for each country to choose the safety level defined in each National Document of Application. The global safety of factor was substituted by the partial safety factors applied to actions and to the strength of materials.