Page 455 - Advanced Design Examples of Seismic Retrofit of Structures

Examples of Nonengineered Buildings Chapter 6 401

TABLE 6.1 Historic Adobe Earthquake Damage Typologies—cont’d

Type Abbreviation Description
Cracks at openings (DT-8) Cracks often begin at the tops of
doors and openings and propagate
upward vertically or at a diagonal.
Cracks can also develop at the lower
corners of windows. These cracks
may be caused by in-plane or out-of-
plane motion
Damage at intersection of (DT-9) Perpendicular walls can separate
perpendicular walls from each other and cause damage
by pounding
Slippage between walls (DT-10) Roof, ceiling, and floor framing
and wood framing often slips at the interface with the
adobe walls. Wood framing is often
not or inadequately attached to the
adobe walls in historic adobe
buildings
Damage at anchorage (DT-11) Crack damage often propagates
and cross-ties from structural anchorage and cross-
ties. It is difficult to avoid stress
concentrations at these locations
which generally lead to cracks and
other damage such as crushing of
material
Local section instability (DT-12) Local wall sections can become
unstable as the result of cracks that
develop at corners of buildings and/
or window and door openings
Horizontal upper-wall (DT-13) Horizontal cracks may develop near
cracks the tops of walls when there is a
bond beam or the roof is anchored to
it. These cracks are caused by the
combination of horizontal forces
and the small vertical compressive
stresses near the top of the wall
Moisture damage (DT-14) Moisture damage at the base of a
contributions to wall can result in wall instability. In
instability some cases, the wall may collapse
out-of-plane because one side of the
wall has been weakened or eroded.
In other cases, saturation or repeated
wet/dry cycles can weaken the
lower adobes causing weakened
slip-planes at the base of the wall
along which the wall can slip and
collapse