Earthquake Characteristics - Fundamentals of Earthquake Engineering - page 35

Table 1.11 Typical damage to building structures.

Masonry and reinforced concrete Steel and composite

Structural element/
system

Observed damage Structural element/

system

Observed damage

Beams Shear failure, concrete cover

spalling, reinforcing bar buckling

Beams Flange and web yielding, local

buckling, brittle fracture

Columns Cracking, crushing, concrete

cover spalling, reinforcing bar
buckling and pull-out, fl exural
and shear failure, short-column
effect

Columns Flange yielding, local

buckling, brittle fracture,
splice failure, member
buckling

Connections Cracking, crushing, reinforcing

bar buckling and pull-out, shear
failure

Braces Local and member buckling,

brittle fracture

Structural walls
and infi lls

X - shaped cracks, crushing,
reinforcing bar buckling,
overturning, rocking, sliding

Connections Yielding, local buckling, brittle

fracture, weld cracks,
excessive panel deformations,
bolt rupture

Foundations Settlement, reinforcing bar pull -

out, rocking, sliding, uplifting

Foundations Bolt anchorage rupture, weld

cracks and fracture, pull- out,
excessive base plate
deformations

Frames Soft and weak storeys, excessive

residual deformations, distress in
diaphragms and connectors,
pounding, rocking, uplifting, fall
of parapets and brick chimneys

Frames Soft and weak storeys,

excessive residual
deformations, distress in
diaphragms and connectors,
pounding, uplifting

in RC beams and columns. Moreover, local buckling may affect steel beams, columns and braces.
Several examples of damage to buildings and bridges are provided in Appendix B, which also contains
a detailed discussion of common structural defi ciencies observed for steel, concrete and masonry
systems. Timber structures have been used extensively especially in Japan, New Zealand and the USA.
They include both older non-engineered single-storey family residences and newer two- to three- storey
apartment and condominium buildings. Wood-framed buildings are inherently lightweight and fl exible;
both features are advantageous under earthquake loading conditions (Ambrose and Vergun, 1999 ).
Low- to medium-rise wood buildings, however, have been affected by structural damage during large
earthquakes (Bertero, 2000). Observed damage consists of cracking in interior walls and brick chim-
neys, cracking and collapse of brick veneer on exterior walls. Wooden constructions have often expe-
rienced failures similar to those of masonry buildings. Indeed, several partial or total collapses are due
to soft and weak storeys, insuffi cient lateral bracing, and inadequate ties and connections between the
components of the building. Inadequate foundation anchorage led to uplifting and sliding in many cases
during recent earthquakes in California (e.g. Baker et al ., 1989; Andreason and Rose, 1994 , among
others).
Lifelines are those services that are vital to the health and safety of communities and the functioning
of urban and industrial regions. These include electric power, gas, water and wastewater systems.
Infrastructures, such as transportation systems (highways and railways), bridges, ports and airports are
also classifi ed as lifelines. Damage to lifelines imposes devastating economic effects on the community.