Robustness of timber structures in seismic areas

Major similarities between robustness assessment and seismic design exist, and significant information can be brought from seismic design to robustness design. As will be discussed, although some methods and limitations considered in seismic design can improve robustness, the capacity of the structure to sustain limited damage without disproportionate effects is significantly more complex. In fact, seismic design can either improve or reduce the resistance of structures to unforeseeable events, depending on the structural type, triggering event, structural material, among others. Based on a case study, the influence of redundancy and ductility on the seismic behavior and robustness of a long-span timber structure is assessed.COST E 5

Assessing the effects of link-repair sequences on road network resilience

Disruptions to transport networks are inevitable and detrimental to the functioning of society. Improving the resilience of transport networks to disruptive events has, therefore, a significant impact on society. Although the resilience of a transport system depends on the ability of the network to sustain the consequences of initial disruption (i.e. robustness) and quickly recover its performance (i.e. rapidity), the latter attracted less attention than robustness. The present paper focuses on quantifying the impacts of recovery processes and, more specifically, link-repair strategies on resilience. Several link-repair strategies are compared across a multitude of perturbation scenarios in the well-known Sioux Falls network. The strategies considered include: (i) the optimal (minimising the disruption consequences over the recovery process), (ii) average (representing a recovery process where the disrupted links are repaired in random order), (iii) flow-based (where the links with the highest traffic flow in the undisrupted network are repaired first), and (iv) criticality-based (where the links whose individual failure result in the highest impacts on the system performance are repaired first) recovery. The results of this comparison are subsequently used to evaluate the correlation between robustness and resilience, and characterise the optimal repair strategy

Using a random road graph model to understand road networks robustness to link failures

Disruptions to the transport system have a greater impact on society and the economy now than ever before due to the increased interconnectivity and interdependency of the economic sectors. The ability of transport systems to maintain functionality despite various disturbances (i.e. robustness) is hence of tremendous importance and has been the focus of research seeking to support transport planning, design and management. These approaches and findings may nevertheless be only valid for the specific networks studied. The present study attempts to find universal insights into road networks robustness by exploring the correlation between different network attributes and network robustness to single, multiple, random and targeted link failures. For this purpose, the common properties of road graphs were identified through a literature review. On this basis, the GREREC model was developed to randomly generate a variety of abstract networks presenting the topological and operational characteristics of real-road networks, on which a robustness analysis was performed. This analysis quantifies the difference between the link criticality rankings when only single-link failures are considered as opposed to when multiple-link failures are considered and the difference between the impact of targeted and random attacks. The influence of the network attributes on the network robustness and on these two differences is shown and discussed. Finally, this analysis is also performed on a set of real road networks to validate the results obtained with the artificial networks

Implementation and calibration of finite-length plastic hinge elements for use in seismic structural collapse analysis

Finite-length plastic hinge (FLPH) models have shown advantages over the concentrated plasticity hinge (CPH) models. However, empirical phenomenological relationships, such as Modified Ibarra–Medina–Krawinkler (ModIMK) deterioration model, were mainly calibrated for use in CPH models. ModIMK relationships are versatile and have been applied to steel, reinforced concrete, and timber structures. Herein, a calibration procedure of FLPH models and a unified algorithm for use of ModIMK relationships in CPH and FLPH models are presented. Results from included examples validate the proposed algorithms, which were implemented in OpenSees. Additionally, results highlight that FPLH models avoid errors and convergence pitfalls of CPH models

Using a hazard-independent approach to understand road-network robustness to multiple disruption scenarios

A range of predictable and unpredictable events can cause road perturbations, disrupting traffic flows and more generally the functioning of society. To manage this threat, stakeholders need to understand the potential impact of a multitude of predictable and unpredictable events. The present paper adopts a hazard-independent approach to assess the robustness (ability to maintain functionality despite disturbances) of the Sioux Falls network to all possible disruptions. This approach allows understanding the impact of a wide range of disruptive events, including random, localised, and targeted link failures. The paper also investigates the predictability of the link combinations whose failure would lead to the highest impacts on the network performance, as well as, the correlation between the link-criticality rankings derived when only single-link failures are considered as opposed to when multiple-link failures are considered. Finally, the sensitivity of the robustness-assessment results to the intensity and distribution of the travel demand is evaluated

Expected implications of climate change on the corrosion of structures

The report presents the work of the Joint Research Centre (JRC) scientific network on adaptation of structural design to climate change addressing the expected implications of a changing climate on the corrosion of structures. The work first outlines recent EU policies supporting the sustainability and climate resilience of infrastructure and buildings. It is highlighted how the construction sector is encouraged to adopt more sustainable and circular economic practices, extend the lifetime of buildings and strive for better performance of buildings and infrastructure throughout their life cycle. The ongoing action plan to adapt European standards to a changing climate is emphasised. The report evaluates the expected variations in climatic factors causing corrosion, provides a state-of-the-art review on climate change induced corrosion of reinforced concrete and steel structures, and presents recent works on the corrosion impact, the costs and effectiveness of adaptation strategies. The effects of corrosion on the seismic performance of structures is addressed as well. In conclusion, this report presents the scientific and technical background to study the expected implications of climate change on the corrosion of structures. The work intends to stimulate debate on the subject, identify further research needs, and serve as a basis for the development of further work relevant to the adaptation to climate change of European standards and policies.JRC.E.4-Safety and Security of Building

Using a random road graph model to understand road networks robustness to link failures

Disruptions to the transport system have a greater impact on society and the economy now than ever before due to the increased interconnectivity and interdependency of the economic sectors. The ability of transport systems to maintain functionality despite various disturbances (i.e. robustness) is hence of tremendous importance and has been the focus of research seeking to support transport planning, design and management. These approaches and findings may nevertheless be only valid for the specific networks studied. The present study attempts to find universal insights into road networks robustness by exploring the correlation between different network attributes and network robustness to single, multiple, random and targeted link failures. For this purpose, the common properties of road graphs were identified through a literature review. On this basis, the GREREC model was developed to randomly generate a variety of abstract networks presenting the topological and operational characteristics of real-road networks, on which a robustness analysis was performed. This analysis quantifies the difference between the link criticality rankings when only single-link failures are considered as opposed to when multiple-link failures are considered and the difference between the impact of targeted and random attacks. The influence of the network attributes on the network robustness and on these two differences is shown and discussed. Finally, this analysis is also performed on a set of real road networks to validate the results obtained with the artificial networks.JRC.C.6-Economics of Climate Change, Energy and Transpor

A margem sul portuguesa profunda

A Margem Sul Portuguesa Profunda (MSPP) define-se neste trabalho como um conjunto de domínios morfotectónicos limitados superiormente por um rebordo de erosão situado geralmente a profundidades superiores a cerca de 1000 m abaixo do nível do mar, que se desvanece progressivamente para leste, na direcção do estreito de Gibraltar. Os processos que moldam a morfologia do fundo do mar na MSPP são de natureza tectónica, magmática, sedimentar e erosiva. Todos estes processos se devem entender no sentido lato pois a sua origem pode ser variada. Assim, os processos tectónicos compreendem deformação distribuída e localizada (dobras e falhas), diapirismo de sal e de argila e vulcanismo de lama. Os processos sedimentares e erosivos podem ser essencialmente controlados pela gravidade (súbitos ou contínuos) ou por correntes oceânicas. Os processos magmáticos contribuíram pontualmente do Jurássico até ao Miocénico superior na edificação de montes submarinos como no caso do monte submarino Coral Patch ou ainda na edificação de intrusões mesozóicas hoje salientes como relevos de dureza no talude continental a noroeste de Sagres. (...)À Fundação para a Ciência e a Tecnologia agradecem-se as seguintes bolsas de pós doutoramento e doutoramento: SFRH/BPD/34798/2007 (TC), SFRH/BPD/42534/2007 (CR), SFRH/BD/31188/2006 (JD), SFRH/BD/17603/2004 (VV), SFRH/BD/46227/2008 (SS). L. Batista agradece o apoio da Estrutura de Missão para os Assuntos do Mar. O Laboratório Nacional de Energia e Geologia (LNEG) agradece o apoio da Landmark Graphics Corporation via the Landmark University Grant Program. Os autores agradecem aos projectos o apoio à investigação realizada NEAREST (Integrated observations from NEAR shore sourcES of Tsunamis: towards an early warning system), MATESPRO (Major Tectonic and Sedimentary Processes on the Portuguese Continental Margin), BIGSETS (Big Sources for Earthquakes and Tsunamis), SWITNAME (Modelação tectónica, numérica e analogica da fronteira de placas a SW da península Ibérica, PDCT/CGE-GIN/59244/2004), ALMOND (Modelação multi-escala da deformação no Golfo de Cádis, PTDC/CTE-GIN/71862/2006), TOPOMED (Plate re-organization in the western Mediterranean: lithospheric causes and topographic consequences TOPOEUROPE/ 0001/2007), SWIMGLO (A ligação dos limites de placas Falhas Glória-SWIM e a sua importância na propagação da deformação tectónica e de ecossistemas profundos no limite de placas Açores-Gibraltar, PTDC/MAR/100522/2008) e EVENT (Integración de nuevas tecnologías en paleosismología: Caracterización de fallas generadoras de terremotos y tsunamis en el Sur de Iberia, CGL2006-12861-C02-02) of the Spanish Ministry of Science and Innovation (MICINN). Uma contribuição do 1713 ISMAR.Peer Reviewe