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Abdessemed M.,Public Works Ministry | Abdessemed M.,Polytechnic School of Algiers | Kenai S.,Blida University | Bali A.,Polytechnic School of Algiers | Kibboua A.,National Earthquake Engineering Center
Construction and Building Materials | Year: 2011

A significant number of existing reinforced-concrete bridges all over the world require maintenance and repair. Hence, the need for a rapid evaluation procedure for the diagnosis of existing bridges. This paper presents the application of a dynamic analysis methodology for structural evaluation of reinforced-concrete bridges. The methodology is based on the application of ambient vibrations non-destructive testing method and the identification of the structure total response using finite element method. A case study of a three span reinforced concrete bridge in a strong seismic activity area in the north of Algeria is analysed. The ambient vibration testing was carried out on the bridge, before and after its repair by the application of carbon fibre composites. The tests were conducted using an acquisition system made up of four accelerometers with three components placed at specific locations on the bridge. The finite element model gave comparable results to the experimental ambient vibrations tests. The modal parameters of the bridge before and after repair were identified by this in situ testing. The application of composite material to strengthen the structure increases the transverse rigidity of the structure and thus its modal frequency. © 2010 Elsevier Ltd. All rights reserved.

Kibboua A.,National Earthquake Engineering Center | Naili M.,National Earthquake Engineering Center | Benouar D.,University of Science and Technology Houari Boumediene | Kehila F.,National Earthquake Engineering Center
Structural Engineering and Mechanics | Year: 2011

This paper illustrates the results of a seismic vulnerability study aimed to derive the fragility curves for typical Algerian reinforced concrete bridge piers using an analytical approach. Fragility curves express the probability of exceeding a certain damage state for a given ground motion intensity (e.g., PGA). In this respect, a set of 41 worldwide accelerometer records from which, 21 Algerian strong motion records are included, have been used in a non-linear dynamic response analyses to assess the damage indices expressed in terms of the bridge displacement ductility, the ultimate ductility, the cyclic loading factor and the cumulative energy ductility. Combining the damage indices defined for 5 damage rank with the ground motion indices, the fragility curves for the bridge piers were derived assuming a lognormal distribution.

Mehani Y.,National Earthquake Engineering Center | Bechtoula H.,National Earthquake Engineering Center | Kibboua A.,National Earthquake Engineering Center | Naili M.,National Earthquake Engineering Center
Structural Engineering and Mechanics | Year: 2013

The main purpose of this paper is to develop seismic fragility curves for existing reinforced concrete, RC, buildings based on the post earthquake field survey and the seismic performance using capacity design. Existing RC buildings constitute approximately 65% of the total stock in Algiers. This type of buildings, RC, was widely used in the past and chosen as the structural type for the future construction program of more than 2 millions apartments all over Algeria. These buildings, suffered moderate to extensive damage after the 2003 Boumerdes earthquake, on May 21st. The determination of analytical seismic fragility curves for low-rise and mid-rise existing RC buildings was carried out based on the consistent and complete post earthquake survey after that event. The information on the damaged existing RC buildings was investigated and evaluated by experts. Thirty four (34) communes (districts) of fifty seven (57), the most populated and affected by earthquake damage were considered in this study. Utilizing the field observed damage data and the Japanese Seismic Index Methodology, based on the capacity design method. Seismic fragility curves were developed for those buildings with a large number data in order to get a statistically significant sample size. According to the construction period and the code design, four types of existing RC buildings were considered. Buildings designed with pre-code (very poor structural behavior before 1955), Buildings designed with low code (poor structural behavior, between 1955-1981), buildings designed with medium code (moderate structural behavior, between 1981-1999) and buildings designed with high code (good structural behavior, after 1999). © 2013 Techno-Press, Ltd.

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