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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Thanks for your attention!! Eduardo Ismael Hernández eduardo.ismael@upaep.mx Tel +52 222 229 9400 ext 7506