Advances in Seismic Design Methodologies - Earthquake Engineering for Structural Design - page 444

444 Earthquake Engineering for Structural Design

Figure 9.37 Direct effect on non-structural components (FEMA 74, 2005)

Building distortion. During an earthquake, building structures distort or bend from
side to side in response to the earthquake. This produces an interaction between
structural elements and non-structural components. The effects of this interaction can
be grouped into two categories: first, the effect of the response of the structural system
on the non-structural components and second, the effect of non-structural components
on the response of the structural system (NISEE, 1997).
Effect of structure to non-structural components. The displacement over the height
of each story, known as story drift, depends on the size of the earthquake and the
characteristics of the particular building structure. Windows, partitions, claddings and
other items, which are tightly located into the structure, are forced to distort with the
same amount of the story drift (Fig. 9.38). Elements made of brittle materials, like
glass, plaster, drywall partitions, and masonry infill, cannot tolerate significant
distortions and they will crack when the building structure pushes directly on them.
Most architectural components, such as façade masonry infilled panels and internal
partitions, are damaged because of this type of action, not because they themselves are
shaken or damaged by inertial forces.

Figure 9.38 Effect of building deformation on architectural component
(FEMA 74, 2005)