Transcript Stone Masonry Presentation.ppsm

IMPROVING THE SEISMIC
PERFORMANCE OF STONE
MASONRY BUILDINGS
SPONSORED BY:
Jitendra Bothara
Beca
New Zealand
Svetlana Brzev
BCIT
Canada
CHAPTERS
Introduction
Seismic Deficiencies and Damage
Patterns
Stone Masonry Construction with
Improved Earthquake Performance
Retrofitting a Stone Masonry Building
Glossary
STONE MASONRY CONSTRUCTION
AROUND THE WORLD
Typically,
stone
Stone
masonry
is
masonry houses
traditional
form ofare
built by the owners
construction
that has
themselves
or for
by local
been
practiced
builders in
without
any
centuries
regions
formal
training
where
stone
is locally
available
KEY BUILDING COMPONENTS
Stone Masonry
Walls:
Foundations:
Floor
Roof
Vaulted
Floors/Roofs
are
from
Inconstructed
mostand
cases,
Structures:
Brick
or
stone
masonry
Key
Components
of a
Timber
Joists
or Trusses
stone
boulders
bonded
stone
masonry
vaults
are
typical
Floor
and
roof
systems
typical
stone
masonry
Timber
Reinforced
floor
construction
Concrete
together
with
mortar.
walls
are
floor/roof
systems
found
may
floors/roofs
be
in
the
form
are
a
ofvaults,
include
masonry
building
include
Types
of
walls
are:
supported
by
in
Mediterranean
Europe
wooden
common
beams
structural/seismic
covered
with
timber
joists
or
trusses,
floor/roof
systems,
uncoursed
random
continuous
stone
and
the Middle
East
wooden
rehabilitation
planks,
practice
ballast
to
fill,
and
reinforced
concrete
walls,
and
foundations
rubble,
semimasonry
strip
and tileuncoursed
replace
the
flooring
original floor
slabs
structures
in historic
dressed,
dressed
footingsand
buildings
stone
masonry
SEISMIC DEFICIENCIES AND DAMAGE
PATTERNS
Key
Deficiencies
of Stone
Floor
and/or Roof
Out-of-Plane
Wall
Damage
and/or
Roof
Masonry
Buildings
Poor Collapse:
Quality
Collapse
fromof
Collapse:
Separation
of
Walls
at
Roof
collapse
is one
of the
In-Plane
Shear

Lack
of
Structural
Construction:
Inadequate
Wall-to-Floor
The
evidence
from
past
Lack
Delamination
of
Structural
of
Integrity
Wall
Depending
on
the
intensity
In
the
2005
Kashmir
Intersections:
major
causes
of
fatalities
Integrity
Cracking:
Foundation
Problems:
Reports
from
past
and
Wall-to-Roof
earthquakes
has
shown of
Adequate
connections
The
Wythes:
seismic
performance
of
earthquake
ground
earthquake
74,000
intersections
arethatinthe
in
masonry
buildings
Damage
to stone
masonry
Wall
Roof
Collapse
Traditional
foundations
earthquakes
confirm
Anchorages:
that
the
presence
of
ring
between
cross
walls
andto
an
Delamination
unreinforced
takes
masonry
place
shaking,
this
failure
people
died,
most
particularly
vulnerable
during
earthquakes,
and
walls
due
to
in-plane
When
Delamination
of
wall
non-engineered
buildings
use
of
low
quality
building
an
anchorage
is not
beams/bands,
or
long
walls
are
critical
for
building
when
vertical
depends
wall
on
layers
how
mechanism
is
buried
under
the
earthquake
effects
due
to
it
can
take
place
when
seismic
effects
(in
the
wythes
are
often
very
shallow
and
materials
and
poor
adequate,
the
walls
alternative
provisions
such
preventing
out-of-plane
well
bulge
the
and
walls
collapse
are
tied
outward
characterized
either
byshear
rubble
ofof
traditional
significant
tensile
and
either
the
walls
lose
the
direction
wall
lengths)
is
inadequate
for
soft
soil

Out-of-plane
wall
collapse
construction
practices
often
perpendicular
to
the
as
ties
or
bandages,
is
very
walltocollapse
together
due
earthquake
and
anchored
ground
to
vertical
cracks
developed
stone
masonry
stresses
developed
when
ability
to
resist
gravity
less
common
than
damage
conditions.
result
inin
significant
ofenhancing
the
earthquake
direction
In-plane
shear
cracking
effective
the
shaking
floor
and
roof
at
the
wall
intersections,
or
dwellings
seismic
forces
are
loads
and
collapse,
or
due
to
out-of-plane
seismic
earthquake
damage
or the
move
away
from
shaking
Poor
quality
of
structural
integrity
by tilting
and
collapse
of
transferred
from
transverse
when
the
roof
structure
effects
destruction.
floors
and
roof,
and
might
construction
an
entire
wall.walls.
walls
to shear
collapses
topple.
 Foundation problems
CONSTRUCTION WITH IMPROVED
EARTHQUAKE PERFORMANCE
Stone Masonry
Building
Structural Integrity
Walls
(Box Action):
Configuration
Size
and Location
of
Construction
details
Bonding
of
wall
Wall
length:
Seismic
Bands
Past
earthquakes
Building
Site:
Floor and
Plan:
Roof have
Building
Elevation:
Openings:
at
wall
intersection:
wythes
with
The
maximum
(Ring
Beams):
shown
that
damage
The
first
stepconcrete
isshould
Reinforced
Building
Construction:
plans
•Foundations:
The
number
and
size ofto
A
stone
masonry
Timber
Bands:
All
intersections
should
through-stones:
distance
between
A
seismic
band
isbe
the
bands:
openings
should
unreinforced
masonry
constructing
asite
new
be
Adequate
regular,
connections
simple,
and
building
should
be
as
In
many
countries,
such
The
building
minimized
since
excessive
be
strengthened
with
Stone
masonry
buildings
Through-stones
are
adjacent
cross
walls
most
critical
buildings
is
building
should
involve
symmetrical.
between
the
roof
as
Turkey,
Nepal,
regular
as
possible
up
should
have
a
openings
weaken
the
wall.
with
RC
bands
stiches
to
ensure
the
long
stones
placed
in
a
building
should
earthquake-resistant
significantly
reduced
Pakistan,
and
India,
careful
selection
and
rafters,
floor
and
its
height.
consistent
soiljoists,
type
•performed
Ideally, openings
in
well
in past
integral,
box
action
of
through
the
wall
to
tie
be
less
than
5
m
provision
in
a
stone
timber
bands
have
been
when
building
review
of
possible
the
lintel
or
roof-level
opposite
walls
should
be of
across
the
entire
earthquakes
the
building
during
used
for
centuries.
wall
wythes
together
when
mud
mortar
is
masonry
building…the
components
are
building
similar
sites
size.
seismic
band
are well
critical
building area.
•earthquake
Openings
should
be located
shaking.
to
prevent
used,
and 7like
m
when
band
acts
a the
ring
connected
and
for
seismic
safety.
away
the wall
delamination.
cement
mortar
is like
or
belt. from
building
vibrates
intersection, and placed as
used.
a monolithic
box
far apart as possible.
RETROFITTING A STONE MASONRY
BUILDING
Building
Seismic Retrofitting: KeyEnhancing
Strategies and
Integrity
Challenges
[were]
used
for
Strengthening
Enhancing
Wall-to-Floor
the
of
Lateral
Wall
Ties:
The following strategies Models
have the
highest
Bands:
Bandages:
Existing stoneshake-table
masonry
testing…to
Intersections:
and
Load
Wall-to-Roof
Resistance
of
Stone
The
rods
help
to
connect
the
Reinforced
concrete
bands
Bandages
are
thin
cost-to-benefit ratio in terms
of
improving
compare
the
seismic
The
integrity
of
abe
timber
roof
When
Connections:
Masonry
wall
Walls:
intersections
buildings
located
walls
in
at
areas
floor
and
of
roof
or
bandages
can
used
as
reinforced
mortar
overlays
the seismic safety of stone
masonry
performance
of
strengthened
can
beand
improved
by
tying
are
•
Installing
Through-stones
deficient…splints
new
steel
inthe
straps
the
levels
thus
prevent
an
alternative
to
ties
to
bonded
to
the
walls
at
high
seismic
risk
can
be
buildings:
and
unstrengthened
roof
components
straps
form
• Jacketing
Casting
of
L-shaped
new with
RC
mortar
topping
separation
ground
enhance
theaduring
overall
lintel,
floor
and/or
eaves
economically
uncoursed
stone
masonry
• Enhancing
integrity ofretrofitted.
entire
building
and
nailing
them
together
overlays
•the
atop
Grouting
the
can
existing
be used
floor
to to
shaking
building
integrity.
levels
(as
an
alternative
buildings…the
strengthened
strengthen
• Wall
Installing
buttresses
these
new
deficient
timber
by ensuring a boxlike seismic
response
RC
bands).
model
of
a stone
masonry
areas.
planks
• Enhancing the wall strength
for
in-plane
building
survived
all 12 tests,
•
Diagonal
bracing
and out-of-plane effects
of
seismic
loads
while
the unstrengthened
• Casting
a new RC slab one
• Improving floor and roof
diaphragm action
collapsed.
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