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- Mainshock-aftershock damage assessment of infilled RC structuresPublication . Furtado, André; Rodrigues, Hugo; Varum, Humberto; Arêde, AntónioThe primary objective of this manuscript is to present a numerical study regarding the mainshock-aftershock damage assessment of infilled reinforced concrete (RC) structures. For this, an 8 storey building was built in the OpenSees software considering different modelling strategies: (i) RC structure without infill masonry walls; (ii) RC structure with infill walls considering only the in-plane behaviour; and (iii) RC structure with infill walls considering the combined in-plane and out-of-plane non-linear behaviour. Two different approaches are proposed to assess the seismic vulnerability of undamaged and damaged structures due to mainshock-aftershock sequences. Both methodologies are described throughout the manuscript. Incremental dynamic analysis were carried out to achieve fragility curves for different damage states of the structures. A comparison between the undamaged and damaged structures’ fragility curves will be presented and discussed which will allow to assess the effect of the mainshock-aftershock. Furthermore, the effect of the infill walls presence and the consideration of the combined in -plane and out-of-plane behaviour will be discussed.
- Seismic Vulnerability Assessment of a Water Supply Network: City of Aveiro Case StudyPublication . Pires, Hélder; Rodrigues, Hugo; Afonso, Armando Silva; Pimentel-Rodrigues, Carla; Rodrigues, FernandaCritical infrastructures have critical importance on societies as they rely on fundamental development and safety aspects. The inoperability of these networks can cause great damage to strategical state-related activities and may reduce the ability to address the results in the aftermath of an accident or catastrophe. Taking in mind that damages in a water supply network do not depend only on the intensity of the disaster, but also on the vulnerability of each component of the entire system, it is important to ensure the ability of these infrastructures to remain operational during and after any disruptive event to prevent the loss of availability of vital goods and services, but also due to the high level of interdependence between different networks, that can lead to a propagation of effects, increasing the level of losses. The seismic vulnerability assessment of water systems is one of the most effective mitigation strategies that will allow to estimate the serviceability of the system and evaluate the estimated direct losses in terms of replacement cost. This paper aims to revise the main seismic risk assessment methodologies available for seismic vulnerability assessment of water networks and based on the selected methodology to present an application to a real network.
- Seismic assessment of a school building in Nepal and analysis of retrofitting solutionsPublication . Rodrigues, Hugo; Furtado, André; Vila-Pouca, Nelson; Varum, Humberto; Barbosa, André R.Recent earthquakes highlighted the vulnerability of some infilled reinforced concrete structures due to the presence and distribution of the infill masonry walls. Buildings such as school buildings and residential buildings are typically not designed considering the contribution of the infill panels to the structure strength and stiffness, when these are subjected to earthquakes. The lack of consideration of the infill panel results in observed poor performance and structural collapses. This manuscript presents a numerical study of a school in Nepal, representative of those existent in the country. Non-linear numerical analyses were carried out to assess the seismic vulnerability in terms of peak inter-storey drifts. In addition, results will be presented and discussed in terms of peak inter-storey drift profiles and peak base shear. Results from a seismic vulnerability assessment of the pre-earthquake structure indicate that the presence of the infill panels in the original structures were responsible for the development a soft-storey mechanism, combined with torsion. Following the seismic vulnerability assessment, four different retrofit solutions were tested and compared with the results of the original structure to gain an understanding on the structural efficiency of each proposed solution. The retrofit solutions proposed revealed to be efficient and reduce the seismic vulnerability. The retrofit solution showing best results correspond to the ones in which reinforced concrete column jacketing was employed.
- Seismic performance of RC precast industrial buildings—learning with the past earthquakesPublication . Batalha, Nádia; Rodrigues, Hugo; Varum, HumbertoPrecast reinforced concrete (RC) industrial buildings have exposed their vulnerability on recent earthquakes, highlighting structural and non-structural damages most related to deficient transferring of horizontal forces namely in connections between elements. Several studies have been carried out on the evaluation of seismic vulnerability of RC structures, motivated mainly by the need of protecting the existent building stock and human lives. However, the same concern is also relative to the industrial building stock, where precast reinforced concrete building is one of the main structural systems. The collapse of such type of structures can result in important losses of human lives and lead to also large economic impact on society. Severe damages can limit its reparability after earthquake events, which result in its demolition and reconstruction. It was this context of damages that emphasized the need for risk assessment to estimate potential damage for future earthquakes. Thus, the main objective of the present paper is to review and identify the main sources that can increase the vulnerability of this typology of buildings to allow the proper seismic assessment of existing precast industrial buildings and solve the inefficient structural and non-structural problems with innovative techniques for its retrofitting.
- Simplified macro‐model for infill masonry walls considering the out‐of‐plane behaviourPublication . Furtado, André; Pinheiro Rodrigues, Hugo Filipe; Arêde, António; Varum, HumbertoOne of the main challenges in earthquake risk mitigation is the assessment of existing buildings not designed according to modern codes and the development of effective techniques to strengthen these structures. Particular attention should be given to RC frame structures with masonry infill panels, as demonstrated by their poor performance in recent earthquakes in Europe. Understanding the seismic behaviour of masonry‐infilled RC frames presents one of the most difficult problems in structural engineering. Analytical tools to evaluate infill–frame interaction and the failure mechanisms need to be further studied. This research intends to develop a simplified macro‐model that takes into account the out‐of‐plane behaviour of the infill panels and the corresponding in‐plane and out‐of‐plane interaction when subjected to seismic loadings. Finally, a vulnerability assessment of an RC building will be performed in order to evaluate the influence of the out‐of‐plane consideration in the building response. Copyright © 2015 John Wiley & Sons, Ltd.