Transcript Case study on directing plastic hinges from columns into beams Scientific Team: asist.dr.ing.

Case study on directing plastic
hinges from columns into beams
Scientific Team:
asist.dr.ing. Ioana Olteanu
prof.dr.ing. Alex Barbat (from UPC, Barcelona, Spain)
ing. Radu Canarache
Bucuresti, Mai 2013
CONTENT:
Natural disasters
Vulnerability
Seismic risk assessment
Case studies
Natural disasters
pests
1%
volcanoes
2%
fires extreme temperature
3%
3%
drought
8%
landslides
5%
floods
31%
earthquake and tsunami
9%
storms
27%
epidemis
11%
meteorological events 69%
earthquakes 9%
The disasters are not natural
The risk is not natural either
hazard
is natural
vulnerability
is not natural
VULNERABILITY
Vulnerability is a set of prevailing or consequential conditions, which adversely
affect an individual, a household or a community's ability to mitigate, prepare for or
respond to the earthquake hazard.
Vulnerability factors:
Population
density
Physical
assets
Economic
activity
Anderson and Woodrow (1989) grouped vulnerabilities into three categories:
Physical/material vulnerability: inherent weakness of the built environment and
lack of access to resources, especially of poor section of the population
Social/organizational vulnerability: inherent weakness in the coping mechanism,
lack of resiliency, lack of commitment
Attitudinal/motivational vulnerability: fatalism, ignorance, and low level of
awareness
Seismic vulnerability, V: element
predisposition to suffer a specific
loss as a result of a seismic action of
a specific intensity S.
Seismic risk index
Seismic hazard, H: probability of occurrence
of a seismic event with a severity greater than
S during a exposure period T.
focus
VULNERABILITY – vulnerable elements in the physical environment
older residential and commercial buildings and infrastructure constructed of
unreinforced masonry (i.e., URM's) or construction materials with inadequate
resistance to lateral forces;
 older non-engineered residential and commercial buildings that have no lateral
resistance and are vulnerable to fire following an earthquake;
 new buildings and infrastructure that have not been sited, designed, and
constructed with adequate enforcement;
 buildings and lifeline systems sited in close proximity to an active fault system, or
on poor soils that either enhance ground shaking or fail through permanent
displacements (e.g., liquefaction and landslides), or in low-lying or coastal areas
subject to either seiches or tsunami flood waves.
 schools and other buildings that have been built to low construction standards.
 communication and control centers that are concentrated in one area.
 hospital facilities that is insufficient for large number of casualties and injuries.
 bridges, overhead crossings and viaducts that are likely to collapse or be
rendered unusable by ground shaking.
 electrical, gas, and water supply lines that are likely to be knocked out of service
by ground failure
Vulnerability factors
Short column
Diagonal crack and shear collapse of the column due to this phenomenon almost lead to the
general collapse of a parking structure (Northridge, California, 1994)
Vulnerability factors
Reinforced concrete frame infill
(a)
(b)
(a) Masonry
infill cracking
(Izmit,
Turcia,
1999) (b)
stiff
masonry
lead of
to discontinuities
the shear of thein
Examples
of collapsed
columns
due to
the forming
of The
short
column
because
columns
Turcia,1999)
1998)
the infill (Adana
masonry- Ceyhan,
(Izmit, Turcia,
Vulnerability factors
Insufficient stiffness due to plates
Structures made of prefabricated elements with inadequate connections (Armenia, 1988)
SEISMIC RISK ASSESSMENT
Capacity spectrum method, ATC-40
Capacity curve
Sa F
Vb
Sa 
1W
Sd 
F
top
PF1 top
F
 

Sd
SEISMIC RISK ASSESSMENT
Capacity spectrum method, ATC-40
Design spectrum
Design spectrum,
AD
Sa-Tformat
Earthquake
recording
from March 1977, PGA=0.20g
0.7 0.7
2.00
0.6
0.6
1.50
1.00
0.5
0.5
Sa(0.2g)
0.50
0.4 0.4
0.00
0.00
0.3 0.3
-0.50
5.00
2
T
Sd = 2 Sa
4π
10.00
15.00
0.2
0.2
-1.00
20.00
25.00
30.00
35.00
40.00
45.00
50.00
-1.500.1
0.1
-2.00 0
0
0.00
0
-2.50
0.5
0.50
1
1.00
1.5
1.50
2
2.00
2.5
T(s)
Sd(cm)
2.50
3
3.00
3.5
3.50
4
4.00
4.5
4.50
5
SEISMIC RISK ASSESSMENT
Capacity spectrum method, ATC-40
Performance point
Spectru de proiectare cu
amortizare de 5%
SaP
SdP
Deplasare spectrala
SEISMIC RISK ASSESSMENT
Capacity spectrum method, ATC-40
Biliniar idealization of the capacity curve
Au
Ay
Dy
Du
SEISMIC RISK ASSESSMENT
Capacity spectrum method, ATC-40
Damage states limits
ds
Au
Ay
1
3
2
0 Dy
Sd1 Sd2
Sd3
4
Du
Sd4
descriere
0
Fara degradari
1
Usor degradate
2
Moderat
3
Sever
4
Complet
Sd,3 = DyS+0.25(D
Sd,4
0.7=uD
D
-D
d,1 =
d,2
yu
y y)
RISCUL SEISMIC
Metoda spectrului de capacitate, ATC-40
Determinarea curbelor de fragilitate
1.0
0.9
Fara degradati
0.8
Slab
Moderat
P(DS>dsi/Sd=Sdi)
0.7
0.6
Sever
0.5
0.4
0.3
Complet
0.2
0.1
0.0
0.0
Sd (cm)
0.5
SdP
1.0
1.5
2.0
2.5
3.0
3.5
4.0
3D FRAME STRUCTURE
3D FRAME STRUCTURE
3D FRAME STRUCTURE
(a)
(b)
Frame type C2: (a) Crack development in the concrete; (b) Reinforcement stresses for a loading
of 1000 kN
3D FRAME STRUCTURE
(a)
(b)
Frame type C3: (a) Crack development in the concrete; (b) Reinforcement stresses for a loading
of 800 kN
3D FRAME STRUCTURE
(a)
(b)
Frame type C4: (a) Crack development in the concrete; (b) Reinforcement stresses for a loading
of 800 kN
3D FRAME STRUCTURE
(a)
(b)
Frame type C5: (a) Crack development in the concrete; (b) Reinforcement stresses for a loading
of 800 kN
3D FRAME STRUCTURE
(a)
(b)
Frame type C6: (a) Crack development in the concrete; (b) Reinforcement stresses for a loading
of 1000 kN
3D FRAME STRUCTURE
(a)
(b)
Plastic hinge development: a – model C2; b – model C6.
3D FRAME STRUCTURE
Cracks and stress development for : a – model C1;
b – model C2; c – model C4; d – model C6.
3D FRAME STRUCTURE
1200
1,200
Forta
taietoare
dela
baza
(KN)
(KN)
baza
taietoare
Forta
1000
1,000
800
800
Cadru cu placa plina de 15 cm - armare normala
600
600
Cadru cu gol la placa 50cm pe colt armareCadru
redusafara placa
Cadru cu inlocuire material pe colturi 50 cm
armare
Placa
plinaredusa
15 cm
400
400
Cadru cu rost 5mm la placa pe colt - armare completa
Cadru cu rost 5mm pe colt - armare redusa
200
200
0
0
0.00
0.00
0.02
0.01
0.04
0.06
0.02
0.08
0.03
0.10
Deplasare (m)
Deplasare (m)
0.12
0.04
0.14
0.05
0.16
0.18
0.06
EFFECT OF INFILL MASONRY
Capacity curves for a 3 level 2D reinforced concrete frame structure with different infill
geometries
EFFECT OF INFILL MASONRY
Plastic hinge development, frame with 4th infill model: (a) without joint, (b) with 5
cm joint
Case study on directing plastic
hinges from columns into beams
Scientific Team:
asist.dr.ing. Ioana Olteanu
prof.dr.ing. Alex Barbat (from UPC, Barcelona, Spain)
ing. Radu Canarache
Iasi, Mai 2013