Eurokod 8, Jordbävningsresistenta konstruktioner

1.1 Scope of EN 1998-3

(1) This document is applicable to the assessment and retrofitting of buildings and bridges in seismic regions, namely as given in a) to c):

a) to provide criteria for the assessment of the seismic performance of existing individual buildings and bridges;

b) to describe the procedure to be followed in selecting necessary corrective measures;

c) to set forth criteria for the design of retrofitting measures (i.e. design, structural analysis including intervention measures, final dimensioning of structural parts and their connections to existing structural members).

NOTE 1 For the purposes of this document, retrofitting covers both the seismic upgrading (e.g. strengthening or adding a passive system) of undamaged structures and the repair and possible upgrading of earthquake-damaged structures.

NOTE 2 Only the most common retrofit techniques are covered in this document. This does not exclude the use of other techniques, which can be developed in each country, based on the strengthening principles of this document.

NOTE 3 Annex D gives flowcharts for the application of this document.

(2) Unless specifically stated, EN 1998-1-1 and EN 1998-5 apply.

(3) Reflecting the performance requirements of EN 1998-1-1:2024, 4.1, this document covers the seismic assessment and retrofitting of buildings and bridges made of the more commonly used structural materials: concrete, steel and composite, timber and masonry.

NOTE Annexes B and C contain additional guidance related to the assessment of timber and masonry structures, respectively, and to their retrofitting when necessary.

(4) This document is intended for the assessment of individual structures, to decide on the need for structural intervention and to design the retrofitting measures that may be necessary. It is not intended for the vulnerability assessment of populations or groups of structures in seismic risk evaluations for various purposes (e.g. for determining insurance risk, for setting risk mitigation priorities, etc.).

(5) This document provides (in its material-specific Clauses 8 to 11) criteria for the verification of the more common retrofitting techniques currently in use.

(6) This document gives specific rules for the assessment and retrofitting relevant to existing buildings and bridges of consequence classes CC1, CC2 and CC3, as defined in EN 1990:2023, 4.3.

(7) Although the provisions of this document are applicable to all common categories of buildings and bridges, the seismic assessment and retrofitting of monuments and heritage structures often requires different types of provisions and approaches, depending on the nature of the monuments and heritage structures. 

1.1 Scope of EN 1998-4

(1) This document is applicable to the seismic design of on-ground and elevated silos, on-ground, elevated and underground tanks, above-ground and buried pipeline systems, towers, masts and chimneys and ancillary elements attached to these structures or in industrial facilities.

(2) Unless specifically stated, EN 1998-1-1 and EN 1998-5 apply.

(3) EN 1998-4 is applicable in complement to the other relevant Eurocodes.

NOTE This document contains only those provisions that, in addition to the provisions of the other relevant Eurocodes, are used for the design of new structures, as listed in (1), in seismic regions. EN 1998-4 complements in this respect the other Eurocodes.

1.2 Assumptions

(1) The assumptions of EN 1998-1-1 apply to this document.

(2) It is assumed that the changes in a) and b) will not take place during the construction phase or during the subsequent life span for all structures covered by EN 1998-4, unless proper justification and verification is provided:

a) substantial changes in the structural systems, supporting structures or attached ancillary elements listed in 1.1(1);

b) substantial changes of masses or mass distribution. This includes, in particular, changes in production, such as specific changes of filling loads, filling states and ancillary elements.