The Revision of the Timber Chapter of En1998-1-2, The New Generation of the Eurocode for Seismic Design of New Buildings

The current Eurocode 8 – Part 1 only provides little information (4 pages) on the seismic design of timber buildings. However, in the last 20 years significant advances occurred, in particular on massive timber structures and multi-storey timber buildings. A new material, cross-laminated timber, has been developed and other engineering wood products have been used more extensively. Innovative fasteners such as self-drilling screws have been developed and are used in more effective joints. Several research projects involving fullscale shaking table tests, static monotonic and fully reversed cyclic tests on subassemblies and components have been performed and advanced FE model capable to predict the seismic behaviour of these structures have been implemented. The new Timber chapter (i.e. Chapter 13 and Annex L) will provide the designer with comprehensive information (about 50 pages) on design of timber buildings for earthquake resistance. The new engineered wood products will be included, and the different lateral load resisting systems will be described. General and specific provisions for dissipative design will be given. A new Table with the default values of the behaviour factors for medium dissipative (ductility class 2) and highly dissipative (ductility class 3) structures will be given for each structural system, together with the limit of the seismic hazard for which a non-dissipative structure (ductility class 1) can be built. Extensive and detailed rules for capacity-based design (at the local/connection, wall and building level) will be provided for each structural system, including the values of the overstrength factors. A Table with the minimum required ductility as defined in the current standard for cyclic testing EN 12512 of dissipative zones will also be provided depending on the structural type and the dissipative subassembly/joint/2D-or 3D connector/connection being tested. Finally yet importantly, a procedure to derive the load-deformation relationships of dissipative timber components from experimental cyclic tests and using analytical formulas will be given in Annex L, as well as equations for the resistances of nondissipative timber components for non-linear static analyses