Simplified guidelines for retrofitting scenarios in the european countries

A large part of the European building stock was built before implementing the recent energy and structural codes, resulting in buildings characterized by deficiencies in terms of comfort, energy savings and structural safety. The retrofitting and rehabilitation of the existing building stock need to be adequately performed, aiming to improve the seismic and energy performance simultaneously. The work summarized here is dedicated to defining priority scenarios for buildings’ retrofitting to improve the seismic safety and energy efficiency of the European Union (EU) building stock. First, the state of the EU building stock is analysed in terms of buildings’ age, types of structures, energy efficiency, energy consumption and energy poverty. Then, the EU climate demands are presented, namely the regions with higher temperature variations, i.e., heating or cooling degree days. The EU seismic risk is also presented and discussed in terms of average annual losses, average annual economic losses and average annual life losses. Based on these input parameters, nine seismic–climate regions in the EU are proposed using a simplified approach. Finally, retrofitting scenarios are proposed for two types of buildings (i.e., masonry and reinforced concrete) based on their seismic–climate region.publishe

Effect of the openings on the seismic response of an infilled reinforced concrete structure

The seismic behavior of the infill masonry infill walls has a significant impact on the global response of reinforced concrete frame structures. One factor influencing its behavior is the existence of openings in the walls, such as doors and windows, which are crucial for the infill seismic performance. Although the numerical simulation of the seismic behavior of RC buildings with infill walls has evolved significantly in recent years in terms of micro- and macro-modelling, most of the existing studies are only related to infill walls without openings. Based on this motivation, four main objectives were defined for this research work: (i) present a simplified modeling approach and its calibration to simulate the seismic behavior of infill walls with central openings such as windows; (ii) evaluate the impact of the openings on the global seismic response of an RC building; (iii) study the impact of the irregular distribution of the infill walls (vertical and in-plane) on the global seismic response of an RC building; and (iv) study the impact of the central openings ratio (i.e., relative percentage between opening and infill wall area) on the global seismic response of an RC building structure. A four-story infilled RC building was used as a case study to perform parametric analyses investigating the impact of the masonry infill walls’ irregular distribution (vertical and in-plan) and their openings ratio. The results are discussed in terms of natural frequencies and vibration modes, initial lateral stiffness, and maximum lateral resistance. This study found that the openings caused a reduction in the natural frequencies of about 20% compared with the full infill (without openings). The openings did not modify the vibration modes. In addition, the openings reduced the initial stiffness by about 20% compared with the model without openings. The maximum strength increased about 50% with the infill walls, but this was reduced by the openings by 20%.publishe

A review of the performance of infilled RC structures in recent earthquakes

The primary objective is to present the most representative types of damage observed in reinforced concrete (RC) structures due to earthquakes. Those damages are divided according to the ten most representative types. Examples and the main reasons that could trigger each failure mechanism are presented. The definition of these damage types is supported by post-earthquake damage reconnaissance missions in Sichuan (China) in 2008, L’Aquila (Italy) in 2009, Lorca (Spain) in 2011, Emilia-Romagna (Italy) in 2012, Gorkha (Nepal) in 2015, Muisne (Ecuador) in 2016 and Chiapas (Mexico) in 2017. An extensive discussion is presented concerning the infill walls’ seismic behaviour and their interaction with the RC structural elements. The presentation of the significant learnings and findings concerning the typical damage herein presented and discussed are compared with the common Southern European construction practice. The impact of the infill walls on the rehabilitation costs of damaged RC buildings is also studied. These costs are compared to those related to the structural damage and rehabilitation of the entire building structure to understand the impact of the infill walls. Finally, a case study is presented to study the effect of implementing simplified retrofitting strategies to prevent the soft-storey mechanism, one of the most common problems observed in past earthquake events.publishe

Influence of seismic loading on axial load variation in reinforced concrete columns

Experimental tests demonstrated the importance of the axial load variation in the seismic response of RC columns, namely, through the reduction in the strength capacity, reduced deformation capacity, and reduced energy dissipation capacity. Thus, this manuscript aims to study the axial load variability of RC columns, according to the plan and height disposition, and assess the relationship between the corresponding column flexure capacity and its influence on the global response of the structure. Hence, three RC structures were modeled using the software SeismoStruct and subjected to non-linear static pushover and dynamic analyses. According to the results, which are assessed in terms of capacity curves, axial load variation, and story/global shear capacity of each model, it can be concluded that the axial load variation is higher in the bottom storys and decreases with the story height of the structure. As observed, the corner columns reached a higher axial load variation than the façade and central columns

Aspectos de desempenho das redes CDPD

Orientador: Nelson Luis Saldanha da FonsecaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Cellular Digital Packet Data Networks (CDPD) é uma tecnologia de redes sem fio que tem como principais características a transmissão digital, tecnologia de rádio, channel hopping e comutação por pacote. A presente dissertação enfoca aspectos do desempenho e dimensionamento das redes CDPD. Propõe-se uma extensão do protocolo DSMA/CD para o transporte de tráfego com prioridade.Abstract: Cellular Digital Packet Data Networks is a wireless network technology which has as main feature the digital transmission, radio technology, channel hopping and packet commutation. In this dissertation, performance aspects and CDPD networks are analyzed. Moreover, a prioritized version of the DSMA/CD protocol is introduced.MestradoMestre em Ciência da Computaçã

Inversão de Registos de Ruído Sísmico Ambiental para Determinação do Modelo de Estrutura do Vale do Tejo

The Lower Tagus Valley is located in the Lower Tagus Sedimentary Basin. The occurrence of earthquakes in this area indicates the presence of seismogenic structures at depth that are still deficiently known due to a thick Cenozoic sedimentary cover. To confirm the velocity model obtained by geophysical and geological data, we use broad-band microtremor measurements and the horizontal to vertical (H/V) spectral ratio method. The H/V curves are inverted, with geological and geophysical constraints, in order to obtain the velocity model above stations located along two profiles: Vila-Franca/Xira-Benavente and Vila Franca de Xira-Samora Correia

Experimental assessment of strengthening strategy to improve the masonry infills out-of-plane behaviour through textile reinforced mortar

Throughout the last years, the study of the masonry infill walls out-of-plane behavior is being observed by the scientific community with special attention, mainly due to damages observed during post-earthquake scenarios, where several number of damages and out-of-plane collapses of infill panels were found. Different causes are pointed to justify the seismic vulnerability of these type of elements, most of all related to deficient construction practices, which are nowadays still applicable Based on this motivation, two experimental quasi-static, full-scale, out-ofplane tests were carried out on RC frames that were built and infilled with a thin masonry wall made up of horizontal hollow clay bricks. The first specimen is representative of the enclosure of a typical existing RC building in the Southern countries in its "as-built" condition. The second specimen was strengthened with textile-reinforced mortar using glass fiber mesh. Both specimens were subjected to semi-cyclic (loading-unloading-reloading) history of imposed displacements by means of small pneumatic jacks through a uniform distributed load. Experimental results will be presented and detailed in terms of out-of-plane force-displacement responses and damage evolution. In the end, the results of the tests are compared to assess the effectiveness of the strengthening technique

Velocity and structural model of the Lower Tagus Basin according to the study of environmental seismic noise

Along his history the Lower Tagus Valley (LTV) region was shaken by several earthquakes, some of them produced in large ruptures of offshore structures located southwest of the Portuguese coastline. Among these is the Lisbon earthquake of 1 November 1755 (M∼8.5-8.7), and other moderates earthquakes that were produced by local sources such as the 1344 (M6.0), 1531 (M7.1) and 1909 (M6.0) earthquakes. Previous simulations [1] have shown high velocity amplification in the region. The model used in the simulations was updated from low to high resolution using all the new available geophysical and geotechnical data on the area (seismic reflection, aeromagnetic, gravimetric, deep wells and geological outcrops) [2]. To confirm this model in the areas where it was derived by potential field methods we use broadband ambient noise measurements collected in about 200 points along seven profiles on the LTV basin, six perpendicular and one parallel to the basin axis. We applied the horizontal to vertical (H/V) spectral ratio method [3] to the seismic noise profiles in order to estimate the distribution of amplification in the basin. The H/V curves obtained reveals the existence of two low frequency peaks centered on 0.2 and 1 Hz [4]. These peaks are strongly related with the thickness of Cenozoic and alluvial sediments. The velocity model obtained by inversion of the H/V curves is in good agreement with borehole data, and results obtained using seismic reflection and gravimetric methods. However, aeromagnetic data overestimates the depth of the base of Cenozoic in the areas where it overlies directly the paleozoic basement, which we attribute either to the existence of Mesozoic units or higher magnetic susceptibilities than expected for the Paleozoic. References: [1] Bezzeghoud, M., Borges, J.F., M., Caldeira (2011). Ground motion simulations of the SW Iberia margin: rupture directivity and earth structure effects. Natural Hazards, pages 1–17. doi:10.1007/s11069-011-9925-2 [2] Torres, R.J.G., (2012). Modelo de velocidade da Bacia do Vale do Tejo: uma abordagem baseada no estudo do ruído sísmico ambiental, Master Thesis, Universidade de Évora, 83pp. [3] Nakamura, Y., 1989. A method for dynamic characteristics estimations of subsurface using microtremors on the ground surface, Quarterly Report, RTRI, Japan, v. 30, p. 25-33. [4] J.A. Furtado, Confirmação do modelo da estrutura 3D do Vale Inverior do Tejo a partir de dados de ruído sísmico ambiente, Master Thesis, Universidade de Évora, 136pp, 2010

Circulating inflammatory mediators and organ dysfunction after cardiovascular surgery with cardiopulmonary bypass: a prospective observational study

INTRODUCTION: Cardiovascular surgery with cardiopulmonary bypass (CPB) has improved in past decades, but inflammatory activation in this setting is still unpredictable and is associated with several postoperative complications. Perioperative levels of macrophage migration inhibitory factor (MIF) and other inflammatory mediators could be implicated in adverse outcomes in cardiac surgery. METHODS: Serum levels of MIF, monocyte chemoattractant protein (MCP)-1, soluble CD40 ligand, IL-6 and IL-10 from 93 patients subjected to CPB were measured by enzyme-linked immunosorbent assay and compared with specific and global postoperative organ dysfunctions through multiple organ dysfunction score (MODS) and sequential organ failure assessment (SOFA). RESULTS: Most of the cytokines measured had a peak of production between 3 and 6 hours after CPB, but maximum levels of MIF occurred earlier, at the cessation of CPB. Among specific organ dysfunctions, the most frequent was hematological, occurring in 82% of the patients. Circulatory impairment was observed in 73.1% of the patients, and 51% of these needed inotropics or vasopressors within the first 24 hours after surgery. The third most frequent dysfunction was pulmonary, occurring in 48.4% of the patients. Preoperative levels of MIF showed a relevant direct correlation with the intensity of global organ dysfunction measured by SOFA (ρ = 0.46, p < 0.001) and MODS (ρ = 0.50, p < 0.001) on the third day after surgery. MCP-1 production was associated with postoperative thrombocytopenia, and MIF was related to the use of a high dose of vasopressors in patients with cardiovascular impairment and also to lower values of the ratio of partial arterial oxygen tension (PaO(2)) to fraction of inspired oxygen (FiO(2)) registered in the first 24 hours after CPB. CONCLUSION: Despite the multifactorial nature of specific or multiple organ dysfunctions, MIF should be explored as a predicting factor of organ dysfunction, or even as a potential therapeutic target in decreasing postoperative complications

Seismic ground motion scenarios in Lower Tagus Valley Basin

Throughout its history the Lower Tagus Valley (LTV) has been struck by several earthquakes which produced important material damage and loss of lives: The 1st of November 1755 Lisbon earthquake and the 1969 earthquake (Mw=7.3), located in the SW Iberia Margin and the 1344, 1531 and 1909 (M= 6 to 7) with epicenter located inside the LTV basin. Since this region is the most highly populated region in Portugal, it is expected that an earthquake of similar magnitude of those that have occurred in the past will cause an enormous destruction and casualties. This fact makes LTV a high priority area for earthquake research in Portugal. In order to overcome the problems related to the absence of geological outcrops, low slip-rates (<0,4 mm/year) and the processes of sedimentation and erosion, we use in this work seismic reflection profiles, potential field data, soundings, wells and geological cartography to obtain a map of the main seismogenic structures and to characterize their seismic potential [1]. Moreover, a 3D structural model has been developed for de LTV based on Seismic reflection, Seismic Noise and potential field data [2,3]. In order to improve assessment of the seismic hazard in the LTV basin, we simulate long-period (0-1 Hz) ground motion time histories for a suite of scenarios earthquakes (Mw =5.5 to 7) within the basin, using fault geometries and the 3D seismic velocity structure based on the previous mentioned works. References [1] Pinto, Carlos C. (2011). Identification of Seismogenic Structures in the Lower Tagus Basin. Master Thesis, Universidade de Évora, 128 pp. [2] Torres, R.J.G., (2012). Modelo de velocidade da Bacia do Vale do Tejo: uma abordagem baseada no estudo do ruído sísmico ambiental, Master Thesis, Universidade de Évora, 83pp. [3] Furtado, J.A (2010). Confirmação do modelo da estrutura 3D do Vale Inverior do Tejo a partir de dados de ruído sísmico ambiente, Master Thesis, Universidade de Évora, 136pp