Assessment of the seismic safety of school buildings in Mexico: A first look

Revista De La Facultad De Ingenieria Universidad Central De Venezuela, 2010

The goals of this paper are (1) to present the methodologies used to perform seismic inspections and to evaluate the associated risk of school buildings in Venezuela and (2) to report preliminary results. A data collection form was designed to gather structural and non-structural information about school buildings. A risk index was defined as function of a hazard index, an occupation index, and a vulnerability index. A total of 286 school buildings were inspected. Preliminary results of 55 inspections are presented in the paper: 19 inspections were performed in Sucre State (PGA=0.4g for T=475 years) and 36 inspections were performed in Carabobo State (PGA=0.3g for T=475 years). 80% of the inspected schools buildings showed vulnerability index values equal or greater than those obtained for the collapsed school buildings during the 1997 Cariaco Earthquake. 55% of the inspected school buildings showed risk index values equal or greater than those obtained for collapsed school buildings during Cariaco Earthquake. The risks indexes so calculated will support technical and administrative decisions, such as establish priorities to perform detailed structural evaluations and seismic rehabilitation of school buildings.

School buildings have frequently collapsed during earthquakes. The 1997 Cariaco earthquake led to the ruin of four reinforced concrete school buildings that were built several years ago. Failures were the result of structural deficiencies: short columns and low lateral strength, stiffness and energy dissipation capacity. 70% of Venezuelan schools are in high hazard regions; about 1,000 are similar to the collapsed schools. With the purpose of developing a national risk reduction program the expected seismic performance of two typical schools was evaluated: One representing schools built 50 years ago (Old-type) and one representing schools built 20-30 years ago (Box-type). They were analyzed utilizing nonlinear pushover techniques and compared with the inventory of schools in Venezuela. Old-type schools were found to need retrofitting in moderate and above seismic zones, and Box-type schools in higher zones. Practical retrofitting is achieved with the addition of auxiliary structures to support the seismic loads, leaving the existing structures to support only the gravity loads. This effort has led to a national program. The initial phase, surveying approximately 28,000 existing schools, has begun.

70% of the about 34,000 Venezuelan schools are in high seismic hazard regions; about 1,000 are similar or identical to the four school buildings that collapsed during the 1997 Cariaco earthquake. This paper describes a national program aiming to evaluate and reduce the risk of existing schools. The steps under way include: (1) Development of a nationwide catalog on a GIS basis of the existing schools that includes type and date of construction, location, number of stories and population; (2) Building risk maps and estimating losses and casualties from future events; (3) Inspection of 250 school buildings located in the higher hazard zones, with emphasis on the older ones, using a data collection form specially designed for schools. A structural score that is correlated with seismic risk is assigned to each building; (4) Detailed studies of 10 standard school types, selected as pilot projects, including in situ dynamic tests and soil and foundation surveys; (5) Development of optimal retrofitting projects. The proposed solutions for the standard schools that collapsed in the 1997 Cariaco earthquake add stiff and ductile auxiliary structures to withstand most of the earthquake loads; (6) Installation of accelerometers in four schools to record future events; (7) Development of a guide for reducing non-structural vulnerabilities; (8) Workshops and production of videos to enhance the level of community awareness and preparation for seismic events.

2002

Results show that traditional buildings (pre-1997) would have large inelastic demands in frequent events and could collapse in larger events. It is expected, however, that modern buildings would have adequate performance even in extreme events. The radical improvement in the expected and observed performance of modern school buildings is due to the increase in the stiffness demands of the 1997 code.

An assessment of the seismic vulnerability of all school buildings located in the districts of Chorrillos and Barranco, Lima, the capital city of Peru, was conducted using a methodology that includes a visual inspection of the structures, an estimation of their expected earthquake behavior, and school population. A total of 28 schools were evaluated in Barranco and 80 in Chorrillos, encompassing all kindergarten, primary, and secondary schools. Four degrees of seismic vulnerability are proposed as a combination of the expected earthquake behavior and school population. Even some new schools are high vulnerable.

Applied sciences, 2022

Featured Application: Based on the risk estimates obtained in this study, the Lisbon City Council defined short-and medium-term risk mitigation plans, starting with a detailed inspection and assessment of the more vulnerable school buildings, in order to mitigate seismic risk on the city council-managed public schools.

Earthquake Spectra, 2004

The authors inspected approximately 300 primary and secondary schools in 87 municipalities of Molise. About 40% were masonry structures, 40% were reinforced concrete (RC) frame structures, and the remaining 20% were a variety of structures. Almost all of them were built without seismic criteria and most had no more than three stories. In this paper we compare the distribution of the damage with the vulnerability classes. The collapses in San Giuliano di Puglia highlight the comparative vulnerabilities related to structural types, construction phases, and location.

Regional seismic scenarios for Venezuelan school buildings are presented, based on a simplified methodology that develops fragility curves to characterize the seismic vulnerability, assess damages, losses and risk levels. The basic hypothesis is that buildings were designed and built in compliance with the seismic code in force at the time of the construction. Adopting a bilinear capacity curve five damage states were defined. The proposed methodology was calibrated by means of comparing the predicted damage with the observed damaged in an ensemble of school buildings affected by the 1997 Cariaco earthquake. A computational tool based on GIS to estimate damages and losses associated with a particular seismic event was developed, using modern seismic attenuation relationships. Seismic risk based on seismic hazard maps is also determined, which facilitates the task of prioritization for structural retrofitting decisions. The computational tool was applied to the evaluation of three regional scenarios.

Buildings, 2023

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

2016

The capital of Mendoza and the surrounding departments are located in the area of the most seismic vulnerability in Argentina. In spite of having suffered destructive earthquakes, the reconstruction was made in the same affected area of the historical earthquake of 1861, or very near, as well as were the educational buildings, having nowadays more than 500 buildings for that purpose. Many of them are from times when no seismic resistance regulations were required. And other ones have been built under regulations that are different from the current ones. The new regulations have achieved a great advance in the structural and not structural design of the buildings, and this is a tool which gives us a starting point to value what has been done in the constructions made in different stages of our history. The lack of structural adaptation of these buildings can generate their collapse and consequently the loss of their occupant’s lives, causing a great social and economic impact in the ...