Primary Element: An element that is essential to the
Seismic Forces: The assumed forces prescribed herein,
ability of the structure to resist earthquake-induced
related to the response of the structure to earthquake
deformations.
motions, to be used in the design of the structure and its
components.
Quality Assurance Plan: A detailed written procedure
Seismic Isolation and Energy Dissipation:
that establishes the systems and components subject to
special inspection and testing.
Design Displacement: The design earthquake
Reference Resistance (D): The resistance (force or
displacement of an isolation or energy dissipation
system, or elements thereof, excluding additional
moment as appropriate) of a member or connection
displacement due to actual and accidental torsion.
computed at the reference end use conditions.
Design Earthquake: A user-specified earthquake for
Registered Design Professional: An architect or engineer,
the design of an isolated building, having ground
registered or licensed to practice professional architecture
shaking criteria described in Chapter 3.
or engineering, as defined by the statutory requirements of
the professional registrations laws of the state in which the
Displacement-Dependent Energy Dissipation
project is to be constructed.
Devices: Devices having mechanical properties such
Required Strength: The load effect (force, moment,
that the force in the device is related to the relative
displacement in the device.
stress, as appropriate) acting on a component or
connection, determined by structural analysis from the
Displacement Restraint System: Collection of
factored loads (using the most appropriate critical load
structural components and elements that limit lateral
displacement of seismically-isolated buildings during
Resistance Factor: A reduction factor applied to member
the maximum considered earthquake.
resistance that accounts for unavoidable deviations of the
Effective Damping: The value of equivalent viscous
actual strength from the nominal value, and the manner
and consequences of failure.
damping corresponding to the energy dissipated by
the building, or element thereof, during a cycle of
Rigid Diaphragm: A diaphragm that meets requirements
response.
of paragraph 5-9b (1).
Energy Dissipation Device (EDD): Non-gravity-
Secondary Component: Those components that are not
load-supporting element designed to dissipate energy
in a stable manner during repeated cycles of
required for lateral force resistance (contrasted to primary
earthquake demand.
components). They may or may not actually resist some
lateral forces.
Energy Dissipation System (EDS): Complete
Secondary Element: An element that does not affect the
collection of all energy dissipation devices, their
supporting framing, and connections.
ability of the structure to resist earthquake-induced
deformations.
Isolation Interface: The boundary between the upper
Seismic Demand: Seismic hazard level commonly
portion of the structure (superstructure), which is
isolated, and the lower portion of the structure, which
expressed in the form of a ground shaking response
moves rigidly with the ground.
spectrum. It may also include an estimate of permanent
ground deformation.
Isolation System: The collection of structural
Seismic Design Category: A classification assigned to a
elements that includes all individual isolator units, all
structural elements that transfer force between
structure based on its Seismic Use Group and the severity of
elements of the isolation system, and all connections
the design earthquake ground motion at the site.
to other structural elements. The isolation system also
includes the wind-restraint system, if such a system is
Seismic-Force-Resisting System: That part of the
used to meet the design requirements of this section.
structural system that has been considered in the design to
provide the required resistance to the shear wall prescribed
Isolator Unit: A horizontally flexible and vertically
herein.
stiff structural element of the isolation system that
C-7
Previous Page
