[PPT] - Seismic vulnerability of the Quinto Orazio Flacco school Alessandra PowerPoint Presentation

SLIDE 1

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26

Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco

Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

SLIDE 2

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

The construction of the main masonry building of the "Quinto Orazio Flacco" school dates back to the year 1933. The three-storey masonry building is characterized by an M-shaped plan with maximum dimensions equal to 57.8 m and 82.4 m respectively in the transversal and longitudinal directions.  The typologies

f

masonry employed are

f three kinds: irregular

quarrystones; claved stone blocks; tufa blocks.  The staircase spaces, the architraves for wide

penings and the floors

are realized in reinforced concrete. MATERIAL PROPERTIES

SLIDE 3

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

In 1963, dictated by the necessity

f

finding further premises, a new reinforced concrete building, separated from the pre-existent masonry

ne, was realized along its free

perimeter. The separation gaps between masonry and concrete buildings are about 2 cm.

SLIDE 4

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

Analysis of the seismic vulnerability of the “Quinto Orazio Flacco” school

Floor H=23.5cm Floor H=23.5cm Floor H=23.5 cm Floor H=22cm Floor H=23.5 cm Floor H=23.5 cm Floor H=36 cm Floor H=23.5cm Floor H=20+5 cm Floor H=20+5 cm Floor H=22cm

57.78 56.14 41.08 14.08 14.36 5 3 . 9 2

Floor H=23.5cm Floor H=23.5cm Floor H=23.5 cm Floor H=36 cm Floor H=23.5cm Floor H=22cm Floor H=22cm Floor H=23.5 cm Floor H=23.5cm Floor H=23.5cm Floor H=23.5cm Floor H=23.5cm Floor H=23.5cm Floor H=23.5cm Floor H=36 cm Floor H=23.5 cm Floor H=23.5cm

15.15 1 5 . 4 9 3 . 5 9 3 . 9 3

Floor H=22cm

y x

REINFORCED CONCRETE MASONRY

POUNDING POUNDING

1. Non-linear

static analyses (pushover) performed separately for the masonry and reinforced concrete buildings (MIDAS Gen).

2. Earthquake-induced

pounding simulations by non-linear time- history analyses (MATLAB algorithm).

SLIDE 5

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

Since the effective modal mass of each fundamental mode in longitudinal and transversal directions amounts to at least 58% of the total mass of the structure, the following lateral load distributions are used for both masonry and reinforced concrete buildings: a “uniform” pattern and a “modal” pattern. PUSHOVER ANALYSIS

1st Mode of vibration: T=0.27 s, Mx%=1.37%, My%=58.36%

Masonry building

2nd Mode of vibration: T=0.26 s, Mx%=57.7%, My%=1.3%

SLIDE 6

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

Since the effective modal mass of each fundamental mode in longitudinal and transversal directions amounts to at least 58% of the total mass of the structure, the following lateral load distributions are used for both masonry and reinforced concrete buildings: a “uniform” pattern and a “modal” pattern. PUSHOVER ANALYSIS

1st Mode of vibration: T=1.48 s, Mx%=0.0%, My%=95.7%;

Reinforced concrete building

2nd Mode of vibration: T=0.98 s, Mx%=98.1%, My%=0.0%.

SLIDE 7

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

The behaviour of the masonry building is simulated by adopting an equivalent frame element model, characterized by an assemblage of pier, spandrel and joint panels. Piers and spandrels are modeled by assuming an elastic-perfectly plastic behaviour based on the plastic hinge concept. In particular: PUSHOVER ANALYSIS Finite Element model Masonry building  a suitable moment-displacement M- plastic hinge (Fig. a.1) is provided at both ends of each element (CEN 2005, P.C.M. 2005, FEMA 2000);  a shear-displacement V- plastic hinge (Fig. a.2) is located at the mid-span (CEN 2005, P.C.M. 2005, FEMA 2000).

0.008H

el

M

u

M 0.004H

el

V

u

V a.1) a.2)

M V

Pier panels

SLIDE 8

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

The reinforced concrete building is treated as a frame element model, in which the spread of inelasticity is implemented through the formation of nonlinear plastic hinges at the frame element’s ends during the incremental loading process. The moment-rotation relationship of a plastic hinge is modelled as a trilinear curve constituted by the elastic segment (AB), the hardening segment (BC) and the softening segment (CD) (CEN 2001, M.I.T 2008). More precisely: PUSHOVER ANALYSIS Finite Element model Reinforced concrete building  pure moment hinges are assigned to beams;  axial-moment hinges are assigned to columns.

cr

M M

y

M

u

M

y u A B C D

SLIDE 9

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

PUSHOVER ANALYSIS Pushover curves – longitudinal direction

Reinforced concrete building Masonry building

The structures under examination are vulnerable to earthquake-induced structural pounding in the longitudinal direction.

Pushover curves in y direction

5000 10000 15000 20000 25000 30000 35000 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Monitored Displacement, d [m]

Base Shear, F [kN]

uniform pattern modal pattern (1st mode)

SLC SLC

Pushover curves in y direction

150 300 450 600 750 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Monitored Displacement, d [m] Base Shear, F [kN] uniform pattern modal pattern (1st mode)

SLC SLC

SLIDE 10

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING  Building separations are insufficient to accommodate the relative motions of the three adjacent structures.  The adjacent buildings are characterized by natural vibration periods sensibly different, which produce out-of-phase vibrations. MIDAS Gen model Numerical model

non-linear viscoelastic

models to simulate impact

elastic-perfectly plastic

approximation of the storey shear forces

simulation of impact by non-linear

viscoelastic models

elastic behaviour of the storey

shear forces

cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d cy7 m7 cy8 Ky8 m8 cy9 Ky9 m9 d Ky7

SLIDE 11

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

Numerical model

         

t t t t t

g y S y y

y M F F y C y M              mass matrix damping matrix shear forces pounding forces ground acceleration Each colliding 3-storey building is modelled as a three-degree-of-freedom system, with each storey’s mass lumped on the floor level.

cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d cy7 m7 cy8 Ky8 m8 cy9 Ky9 m9 d Ky7

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Just traslational degrees of freedom are considered, while torsional effects are neglected.

SLIDE 12

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Numerical model

         

t t t t t

g y S y y

y M F F y C y M              mass matrix ground acceleration

                                

9 8 7 6 5 4 3 2 1

m m m m m m m m m M

                   

                                t y t y t y t y t y t y t y t y t y t

9 8 7 6 5 4 3 2 1

                    y

                   

                                t y t y t y t y t y t y t y t y t y t

g g g g g g g g g

                    g y

cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d cy7 m7 cy8 Ky8 m8 cy9 Ky9 m9 d Ky7

SLIDE 13

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th- 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Numerical model

         

t t t t t

g y S y y

y M F F y C y M              damping matrix

                                                  

9 9 9 9 8 8 8 8 7 6 6 6 6 5 5 5 5 4 3 3 3 3 2 2 2 2 1 y y y y y y y y y y y y y y y y y y y y y y y y y y y y

c c c c c c c c c c c c c c c c c c c c c c c c c c c C

cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d cy7 m7 cy8 Ky8 m8 cy9 Ky9 m9 d Ky7

SLIDE 14

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Numerical model

         

t t t t t

g y S y y

y M F F y C y M              inelastic storey shear forces elastic range

   

t y K t F

i yi S yi



 

7 , 4 , 1  i

       

t y t y K t F

i i yi S yi 1 

 

 

9 , 8 , 6 , 5 , 3 , 2  i plastic range

 

Y yi S yi

F t F 

 

9 ,...., 1  i

                               

                                       t F t F t F t F t F t F t F t F t F t F t F t F t F t F t F t

S y S y S y S y S y S y S y S y S y S y S y S y S y S y S y S y 9 9 8 8 7 6 6 5 5 4 3 3 2 2 1

F

cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d cy7 m7 cy8 Ky8 m8 cy9 Ky9 m9 d Ky7

SLIDE 15

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Numerical model

         

t t t t t

g y S y y

y M F F y C y M              pounding forces - Hertz’s contact law

                         

                                          t F t F t F t F t F t F t F t F t F t F t F t F t

y y y y y y y y y y y y y 69 58 47 69 36 58 25 47 14 36 25 14

F

 

 t Fyij

       

t t c t t F

ij ij ij yij

    

2 3

 

 t

ij



 

 t

ij

 

   

t t F

ij yij 2 3

 

 

 t

ij



 

 t

ij

 

     

d t y t y t

j i ij

   

   

j i j i ij ij

m m m m t t c      2

cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d cy7 m7 cy8 Ky8 m8 cy9 Ky9 m9 d Ky7

 

 t

ij



SLIDE 16

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Numerical model

         

t t t t t

g y S y y

y M F F y C y M              pounding forces - Hertz’s contact law

                         

                                          t F t F t F t F t F t F t F t F t F t F t F t F t

y y y y y y y y y y y y y 69 58 47 69 36 58 25 47 14 36 25 14

F

 

 t Fyij

 

 t

ij



       

t t c t t F

ij ij ij yij

    

2 3

 

 t

ij



 

 t

ij

 

   

t t F

ij yij 2 3

 

 

 t

ij



 

 t

ij

 

     

d t y t y t

j i ij

   

   

j i j i ij ij

m m m m t t c      2

   

16 16 9 1 2 5 9

2

      e e e

j i j i

v v v v e   

' '

coefficient of restitution impact-damping ratio stiffness parameter

SLIDE 17

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Numerical algorithm

         

t t t t t

g y S y y

y M F F y C y M              The initial value problem of the second order is transformed into a problem of the first

rder:

     

y t t t , ~ ~ F Υ A Υ M     

     

      t t t y y Υ         M I M

9 9 9 9 9 9

~

x x x

        

y x x x

C I A

9

9 9 9 9 9

       

            t t t y t

S y y g

y M F F F  

9

, ~

with: This transformation allows to use suitable numerical solvers provided by MATLAB software, such as ode15s.

SLIDE 18

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Analysis results

Time [s]

0.0E+00 5.0E+05 1.0E+06 1.5E+06 5 10 15 20

Pounding force [N]

.

Time [s]

0.0E+00 5.0E+05 1.0E+06 1.5E+06 5 10 15 20

Pounding force [N]

.

Time [s]

0.0E+00 5.0E+05 1.0E+06 1.5E+06 5 10 15 20

Pounding force [N]

.

Fy

(1)

Fy

(2)

Fy

(3)

Time [s]

0.004
0.003
0.002
0.001

0.001 0.002 0.003 0.004 5 10 15 20

Displacement [m]

.

Time [s]

0.004
0.003
0.002
0.001

0.001 0.002 0.003 0.004 5 10 15 20

Displacement [m]

.

Time [s]

0.004
0.003
0.002
0.001

0.001 0.002 0.003 0.004 5 10 15 20

Displacement [m]

.

y1 y2 y3 Left masonry body

Maximum

displacement: node 3 y3= 4 mm

Maximum pounding force:

node 3 Fy

(3)=1.4.106 N

cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d cy7 m7 cy8 Ky8 m8 cy9 Ky9 m9 d Ky7

Max pounding effects

SLIDE 19

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Analysis results Reinforced concrete buiding

Maximum

displacement: node 6 y6= 4 cm

Maximum pounding force:

node 6 Fy

(6)=1.8.106 N

cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d cy7 m7 cy8 Ky8 m8 cy9 Ky9 m9 d Ky7

Max pounding effects

Fy

(4)

Fy

(5)

Fy

(6)

Time [s]

2.0E+06
1.0E+06

0.0E+00 1.0E+06 2.0E+06 5 10 15 20

Pounding force [N] . Time [s]

2.0E+06
1.0E+06

0.0E+00 1.0E+06 2.0E+06 5 10 15 20

Pounding force [N]

.

Time [s]

2.0E+06
1.0E+06

0.0E+00 1.0E+06 2.0E+06 5 10 15 20

Pounding force [N] .

y4 y5 y6

Time [s]

0.03
0.02
0.01

0.01 0.02 0.03 5 10 15 20

Displacement [m]

.

Time [s]

0.03
0.02
0.01

0.01 0.02 0.03 5 10 15 20

Displacement [m]

.

Time [s]

0.03
0.02
0.01

0.01 0.02 0.03 5 10 15 20

Displacement [m]

.

SLIDE 20

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy EARTHQUAKE-INDUCED STRUCTURAL POUNDING

Analysis results Left masonry body Fy

(3)

Time [s]

0.0E+00 5.0E+05 1.0E+06 1.5E+06 5 10 15 20

Pounding force [N]

.

y3

Time [s]

0.004
0.003
0.002
0.001

0.001 0.002 0.003 0.004 5 10 15 20

Displacement [m]

.

Reinforced concrete building Fy

(6)

Time [s]

2.0E+06
1.0E+06

0.0E+00 1.0E+06 2.0E+06 5 10 15 20

Pounding force [N] .

y6

Time [s]

0.03
0.02
0.01

0.01 0.02 0.03 5 10 15 20

Displacement [m]

.

The contact points at the level of the third storeys are the most critical ones for the pounding problem since collisions occur twenty times during the earthquake and pounding force reaches its maximum value.

SLIDE 21

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy EARTHQUAKE-INDUCED STRUCTURAL POUNDING

Analysis results Left masonry body Fy

(3)

Time [s]

0.0E+00 5.0E+05 1.0E+06 1.5E+06 5 10 15 20

Pounding force [N]

.

y3

Time [s]

0.004
0.003
0.002
0.001

0.001 0.002 0.003 0.004 5 10 15 20

Displacement [m]

.

Reinforced concrete building Fy

(6)

Time [s]

2.0E+06
1.0E+06

0.0E+00 1.0E+06 2.0E+06 5 10 15 20

Pounding force [N] .

y6

Time [s]

0.03
0.02
0.01

0.01 0.02 0.03 5 10 15 20

Displacement [m]

.

Under the seismic action the response of the lighter and more flexible reinforced- concrete building is significant, while the displacements of the heavier and stiffer masonry bodies are nearly negligible.

SLIDE 22

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Left masonry body – node 3 Reinforced concrete building – node 6

Friction forces, which develop at the time of collisions, lead to a reduction of the overall response of the reinforced concrete building and to a phase shift

Comparison between pounding response and independent vibrations

Time [s]

0.06
0.05
0.04
0.03
0.02
0.01

0.01 0.02 0.03 0.04 0.05 5 10 15 20

Displacement [m] .

pounding no pounding

Time [s]

0.004
0.003
0.002
0.001

0.001 0.002 0.003 0.004 5 10 15 20

Displacement [m] .

pounding no pounding

SLIDE 23

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Reinforced concrete building – Shear force time-histories, node 4

The values of both peak displacements and storey shear forces of the reinforced concrete building due to pounding decrease with respect to the independent vibration case.

Comparison between pounding response and independent vibrations

Time [s]

1.0E+06
5.0E+05

0.0E+00 5.0E+05 1.0E+06 5 10 15 20

Shear force FS

y 4 [N]

POUNDING INVOLVED RESPONSE INDIPENDENT VIBRATION

Time [s]

1.0E+06
5.0E+05

0.0E+00 5.0E+05 1.0E+06 5 10 15 20

Shear force FS

y 4 [N]

no-pounding

SLIDE 24

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING

The just described results derive from the particular position of the reinforced concrete building, situated between two bodies of the masonry one. In fact in absence of one of the two masonry bodies the response of the reinforced concrete building would increase due to structural pounding.

Three adjacent structures Two adjacent structures

cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d cy7 m7 cy8 Ky8 m8 cy9 Ky9 m9 d Ky7 cy1 Ky1 m1 cy2 Ky2 m2 cy3 Ky3 m3 cy4 Ky4 m4 cy5 Ky5 m5 cy6 Ky6 m6 d

SLIDE 25

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

EARTHQUAKE-INDUCED STRUCTURAL POUNDING Three adjacent structures Two adjacent structures y6

Time [s]

0.06
0.05
0.04
0.03
0.02
0.01

0.01 0.02 0.03 0.04 0.05 0.06 5 10 15 20

Displacement [m] .

pounding no pounding

y6

Time [s]

0.06
0.05
0.04
0.03
0.02
0.01

0.01 0.02 0.03 0.04 0.05 5 10 15 20

Displacement [m] .

pounding no pounding

The just described results derive from the particular position of the reinforced concrete building, situated between two bodies of the masonry one. In fact in absence of one of the two masonry bodies the response of the reinforced concrete building would increase due to structural pounding.

SLIDE 26

Urban Habitat Constructions under Catastrophic Events

FINAL CONFERENCE. Naples, 16th - 18th September 2010

COST Action C26 Seismic vulnerability of the “Quinto Orazio Flacco” school

Alessandra Fiore & Pietro Monaco Politecnico di Bari, Department of Civil and Environmental Engineering, Bari, Italy

CONCLUDING REMARKS

In this study a detailed investigation of the seismic vulnerability of a complex case study,

including pushover and time-history analyses, has been presented.

In order to investigate the pounding-involved response, a suitable numerical algorithm has been

elaborated by MATLAB software. The algorithm allows to take into account both a non-linear viscoelastic model to simulate impact and a non-linear behaviour of the storey shear forces, differently from many commercial softwares which admit just one non-linearity. It represents a simple and effective method for properly simulating, with a small numerical burden, the seismic-pounding response between three colliding structures. These aspects make the presented procedure particularly useful for practical purpose. REFERENCES

Jankowski, R. 2008. Earthquake-induced pounding between equal height buildings with substantially different dynamic properties. Engineering Structures 30: 2818–2829. Magenes, G. & Calvi, M. 1997. In-plane seismic response of brick masonry walls. Earthquake Eng Struct Dyn J 26: 1091-1112. Muthukumar, S. & DesRoches, R. 2006. A Hertz contact model with non-linear damping for pounding simulation. Earth-quake Engng. Struct. Dyn. 35: 811-828.