Advances in Seismic Design Methodologies - Earthquake Engineering for Structural Design - page 442

442 Earthquake Engineering for Structural Design

One can see that, in case of these types of civil buildings, the cost of structural
systems is the lowest percentage of investments (8 to 18%), followed by contents (17
to 44%); the non-structural component costs are the majority (48 to 70%), in function
of the building functions. Clearly, the investment in non-structural components and
building contents (82 to 92%) is far greater than the one for structural components and
framing. In some cases, such as art museums, high-tech laboratories or computer
centers, the values of non-structural components, especially the building contents,
exceed by far the other investment costs. Thus, a large portion of the potential losses
for owners, occupant insurance companies or financial institutions is associated with
non-structural components. Therefore, the increasing interest on the development of
protection measures to reduce this kind of losses is not surprising.

9.6.2 Non-structural ComponentTypes

The different types of non-structural components can be subdivided into three groups
(Fig. 9.36):
- Architectural elements , like exterior curtain wall, prefabricated panel, glazing,
claddings, interior non-load bearing partition, suspended ceilings, parapets,
penthouse, chimney, appendages and ornamentations, etc.
- Mechanical and electrical utility components , like elevators or escalators, air
conditioning equipments, boilers, storage tanks, heating systems, ventilations,
piping systems, plumbing, fire protection systems, electric motors, etc.
- Contents, like record storages, movable partitions, production equipment and
systems, computer and communication equipments, furniture, etc.

9.6.3 PrimaryCausesofNon-structural Damage

The seismic risk for a particular non-structural component at a given facility is
governed by the regional seismicity, proximity to an active fault, local soil condition,
dynamic characteristics of the building structure and non-structural components, their
bracing and anchorage to the structure, location of the non-structural component within
the structure, function of the facility, importance of the particular component to the
operation of the facility (FEMA 74, 2005).
The earthquake shakes the ground in all directions (horizontal and vertical).
Therefore, the non-structural components must be specially designed to resist the
earthquake forces in a variety of directions. Earthquake ground shaking has several
primary effects on non-structural components in buildings. These are inertial or
shaking effects on the non-structural elements themselves, distortions imposed on non-
structural components when building structure sways back and forth, the effect of the
structure on non-structural components, and the pounding effects at the interface
between adjacent structures.