CONTENT 5.1 SEISMIC BEHAVIOUR ... - CIB-W18

shear walls. Pseudo-dynamic test was also conducted on the same type of
shear walls and the experimental results were compared with the calculation
by non-linear earthquake response analysis and the equivalent linear
response analysis.
Viscous damping is one of the issues difficult to determine. In general
damping factor of 2 to 5% is assumed for dynamic analysis. In this study,
high-speed loading test was conducted to determine the damping factor of
wood-framed shear walls. It was found that the loading rate has an effect
on the lateral resistance at the horizontal displacement of 10 to 70 mm, but
it makes no influence on the load carrying capacity of shear walls.
Conclusions
Simulation by Non-linear time-history earthquake analysis agrees comparatively
well with pseudo-dynamic test results. This kind of model is appropriate
for predicting seismic behaviour of wood-framed shear walls.
Equivalent linear response method using equivalent viscous damping ratio
also gives generally good approximation to determine the maxima displacement
response, however special consideration should be taken for
some kind of seism. High speed test of shear walls showed that we can expect
2 to 5% damping factor up to horizontal displacement of approximately
70mm (story drift of 1/35), but we can not exp viscous damping at
a large deformation in wood-framed shear walls.
35-15-5 E Fournely, P Racher
Cyclic and seismic performances of a timber-concrete system - local
and full scale experimental results
Introduction
Timber-concrete composite floors are light solutions to comply with design
criteria: stiffness, load capacity, fire barrier and resistance, phonic
isolation, comfort toward vibrations... Most of these characteristics are
particularly important in seismic zone. A lot of mechanical functions have
to be assumed by a floor in a structure undergoing severe vertical and horizontal
loading. Obviously, bending strength is the first function of a floor.
Nevertheless, diaphragm function and connection with vertical structure is
also extremely important. The total or semi-rigid connection of to layers
provides a large strength for floor elements in bending. This connection also
undergoes shear forces in order to transfer horizontal loading (wind,
buckling effects, seismic actions...) from beams to diaphragm and from diaphragm
or beams to vertical structures. Figure 1 gives an illustration of
different configurations for a composite floor.
35-15-7 A Ceccotti, T Toratti, B Dujic
Design of timber structures in seismic zones according to EC8- 2002
version
Introduction
Eurocode 8 is the European code for "Design of structures for earthquake
resistance". Part 1 includes "General rules, seismic actions and rules for
buildings". Chapter 5 of Part 1 is devoted to specific rules for concrete
buildings, chapter 6 is for steel buildings, chapter 7 for steel-concrete
composite buildings, chapter 8 for timber buildings, and finally chapter 9
is for masonry buildings. The final draft (prEN 1998-1) is dated May 2002
and it is now ready to undergo the procedure to be accepted as an EN
standard. This version of the code supersedes the previous 1994 version
(ENV 1998-1). The intention of this paper is to highlight the major differences
between the two versions and their consequences on timber buildings
design. Finally a four storey building design example is provided to
non-European Colleagues for possible inter-codes comparisons.
Conclusions
Eurocode 8 is a seismic design code that considers the same design philosophy
for all building materials. In particular the designer of timber structures
is allowed to perform a global elastic analysis. Eurocode 8 presents
few relatively simple and conservative design rules, which are easy to apply,
for the most important structural forms, classified according to their
ductility and energy dissipation level. Last version of the code (prEN,
2002) leaves basically untouched the design dissipative structures while
increases the demand for non-dissipative designed structures.
CIB-W18 Timber Structures – A review of meeting 1-43 5 SPECIAL ACTIONS page 5.19