1. Eduardo Ismael Hernández UPAEP University, MEXICO
Structural Reliability for School Buildings in Seismic Regions of Mexico using Ambient Vibration
Eduardo Ismael Hernández
UPAEP University, MEXICO

2. Skopje, Macedonia, 29, 30 and 31th May, 2013
CONTENT
Background
Structural ReliabilityAnalysis
Estimating Linear and Non-linear Responses
Application and Results
Final Coments
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

3. Skopje, Macedonia, 29, 30 and 31th May, 2013
Background
Considering the impact of earthquakes on society (loss of life and property), it has been recognized around the world about the importance of mitigating the risk associated with this phenomenon.
Moreover, the margins of uncertainty that affect our ability to predict and characterize seismic intensity level is very high, this uncertainty affect our understanding of the relationship between the actual properties of the constructions and the assumed values in the structural design process.
The reliability measure is useful for estimating the seismic risk level and for the establishment of the rehabilitation strategies on buildings.
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

4. Skopje, Macedonia, 29, 30 and 31th May, 2013
Background
In this work we are interested in school buildings, according to the structural regulations in Mexico these buildings belong to group A and are considered as critical, so after a seismic event they must maintain appropriate security levels.
There are some studies to estimate the level of vulnerability Grant et al., (2007) propose a prioritization scheme for assessing the seismic risk level of school buildings in Italy, in this scheme it is assumed that the seismic hazard in the country is known, plus it has a database from the entire school infrastructure with the most general characteristics of the buildings.
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

5. STRUCTURAL RELIABILITY ANALYSIS
Displacement-based criteria for earthquake resistant design are based on the concept that the event of reaching a given performance limit is associated with the condition that the structural distortion reaches a value equal to the corresponding deformation capacity.
According to this, the estimation of the seismic reliability of complex nonlinear systems for given values of the ground-motion intensity is ordinarily based on a measure of the probability that, for an ensemble of earthquake excitations with a specified intensity, the ratio of the peak absolute value of the nonlinear displacement response demand of the system to the corresponding deformation capacity is greater than unity (Esteva et al. 2010).
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

6. STRUCTURAL RELIABILITY ANALYSIS
Secant Stiffness Reduction Index (ISSR)
ISSR<1.0, survival condition
ISSR=1.0, collapse condition K0 K
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

7. LINEAR AND NON LINEAR RESPONSES
Estimation of the frequencies of the building using ambient vibration approach
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

8. LINEAR AND NON LINEAR RESPONSES
Estimation of the frequencies of the building using ambient vibration approach
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

9. LINEAR AND NON LINEAR RESPONSES
Pushover analysis
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

10. LINEAR AND NON LINEAR RESPONSES
Dynamic non-linear analysis
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

11. Skopje, Macedonia, 29, 30 and 31th May, 2013
APPLICATION
High School Building, UPAEP
3 levels
Reinforced concrete structure
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

12. Skopje, Macedonia, 29, 30 and 31th May, 2013
APPLICATION
Mathematical model for non-linear response history and pushover analysis
Uncertainties on gravitational loads and mechanical properties were considered using Montecarlo simulation.
Wang and Shah (1987) model was adopted to represent the constitutive functions describing the bending behaviour of the critical sections at the ends of beams and columns.
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

13. Skopje, Macedonia, 29, 30 and 31th May, 2013
APPLICATION
Seismicity in Mexico
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

14. Skopje, Macedonia, 29, 30 and 31th May, 2013
APPLICATION
Seismic excitation
Ground motion time history used for dynamic non-linear analysis, recorded at UPAEP Station
Pseudo-acceleration response spectrum with damping ratio equal to 0.05
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

15. Skopje, Macedonia, 29, 30 and 31th May, 2013
RESULTS
Experimental values of the frequency for each mode of the building
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

16. Skopje, Macedonia, 29, 30 and 31th May, 2013
RESULTS
Experimental and analytical values of the frequency for each mode of the building
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

17. Skopje, Macedonia, 29, 30 and 31th May, 2013
RESULTS
Pushover curve obtained from the building in the longitudinal direction
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

18. Skopje, Macedonia, 29, 30 and 31th May, 2013
RESULTS
Example of the seismic response computed from the step by step analysis using DRAIN software (Powel, 1973)
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

19. Skopje, Macedonia, 29, 30 and 31th May, 2013
RESULTS
Values of ISSR obtained from Equation 1, in terms of normalized seismic intensity
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

20. Skopje, Macedonia, 29, 30 and 31th May, 2013
FINAL COMENTS
In this work a procedure for estimating structural reliability of school buildings was presented.
The procedure takes into account the evaluation of some dynamic properties using ambient vibration records, these properties are useful to calibrate analytical models of the buildings.
The procedure employs a damage index that considers the reduction of secant stiffness of the structural system when this is subjected to an earthquake with given intensity.
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

21. Skopje, Macedonia, 29, 30 and 31th May, 2013
FINAL COMENTS
After analysing the results we can conclude that the building studied presents an acceptable level of reliability.
Finally, the procedure presented here can be used to other kind of existing buildings and the information obtained can be useful for mitigating the seismic risk of school buildings in Mexico.
TITULO DE LA PRESENTACION HASTA DOS LINEAS
Skopje, Macedonia, 29, 30 and 31th May, 2013

22. Thanks for your attention!!
Eduardo Ismael Hernández
Tel ext 7506