Resilience assessment of high damping rubber bearings in beyond-design conditions

Passive isolation systems are an established solution for the design of civil engineering structures that are required to provide superior performances in the case of a seismic event. Although their application to the seismic protection of bridges is currently limited, isolation systems are likely to become more widespread in the design of strategic infrastructures and facilities. In this work numerical investigations on the ultimate limit state conditions of filled high damping rubber bearings under cyclic shear loading are presented, focusing on the influence of the axial load with respect to the device

Indirect structural health monitoring (iSHM) of transport infrastructure in the digital age

Workshop reportCopyright © Joint Research Centre (European Commission). The existing European motorway infrastructure network is prone to ageing and subject to natural events (e.g. climate change) and hazards (e.g. earthquakes), necessitating immediate actions for its maintenance and safety. Within this context, the structural health monitoring (SHM) framework allows a quantitative assessment of the structural integrity, serviceability and performance, facilitating better-informed decisions for the management of the existing infrastructure. The European Commission Joint Research Centre (JRC) established the exploratory research project MITICA (Monitoring Transport Infrastructures with Connected and Automated vehicles) to investigate the opportunity to use novel methods for infrastructure motoring, aiming at the efficient maintenance of the European aging road infrastructure. This report summarizes the discussion and the outcomes of a workshop held at the JRC in Ispra (Italy) on June 6-7 2022, as part of the MITICA project. Considering the EU priority “A Europe fit for the digital age”, the workshop was dedicated to SHM and its application to civil infrastructure, focusing on innovative indirect structural health monitoring (iSHM) approaches that rely on the vehicle-bridge interaction and the deployment of sensor-equipped vehicles for the monitoring of the existing bridge infrastructure. The report aims to become a reference document in the area of iSHM using passing vehicles, for both scholars and policy makers

Research needs towards a resilient community: Vulnerability reduction, infrastructural systems model, loss assessment, resilience-based design and emergency management

Most of the literature on resilience is devoted to its assessment. It seems time to move from analysis to design, to develop the tools needed to enhance resilience. Resilience enhancement, a close relative of the less fashionable risk mitigation, adds to the latter, at least in the general perception, a systemic dimension. Resilience is often paired with community, and the latter is a system. This chapter therefore discusses strategies to enhance resilience, endorses one of prevention rather than cure, and focuses in the remainder on the role played by systemic analysis, i.e. the analysis of the built environment modelled beyond a simple collection of physical assets, with due care to the associated interdependencies. Research needs are identified and include challenges in network modelling, the replacement of generic fragility curves for components, how to deal with evolving state of information

SOME ASPECTS ON 3D BASE ISOLATION OF HEAVY AND LIGHTWEIGHT STRUCTURES WITH TMD

Some aspects related to the 3-D base isolation of structures are presented in this paper through a numerical approach. A traditional horizontal base isolation system with the use of high damping rubber bearings (HDRB) is coupled with a tuned mass damper (TMD) in the vertical direction. Both lightweight (e.g. artworks or special equipment) and massive structures (a nuclear power plant building) have been considered and possible positive and negative aspects from the implementation of the proposed hybrid control strategy are investigated. It is found that the TMD is able to provide a reliable source of energy dissipation, and to control the vertical motion of the structure, only when this has a low value of damping. For damping values that approximately exceed the 5% limit, the positive effects of TMD are negligible, if not worsening

Some aspects on 3D base isolation of heavy and lightweight structures with TMD

Some aspects related to the 3-D base isolation of structures are presented in this paper through a numerical approach. A traditional horizontal base isolation system with the use of high damping rubber bearings (HDRB) is coupled with a tuned mass damper (TMD) in the vertical direction. Both lightweight (e.g. artworks or special equipment) and massive structures (a nuclear power plant building) have been considered and possible positive and negative aspects from the implementation of the proposed hybrid control strategy are investigated. It is found that the TMD is able to provide a reliable source of energy dissipation, and to control the vertical motion of the structure, only when this has a low value of damping. For damping values that approximately exceed the 5% limit, the positive effects of TMD are negligible, if not worsening

The PEOPLES Resilience Framework: A conceptual approach to quantify community resilience

Over the past years, the concept of resilience has gained attention recognizing the fact that not all threats or disasters can be averted. In fact, communities around the world are turning their attention to efforts and ways that can enhance their resilience against extreme events in any dimensions of life. Resilience is becoming increasingly important for modern societies as states come to accept that they cannot prevent every risk from being realized but rather must learn to adapt and manage risks in a way that minimizes impact on human and other systems. This paper presents a holistic framework for defining and measuring disaster resilience for a community at scales ranging from individual structures (e.g. hospitals) and smaller communities (neighborhoods) to entire regions. Seven dimensions of community resilience have been identified and are represented by the acronym PEOPLES: Population and Demographics, Environmental/ Ecosystem, Organized Governmental Services, Physical Infrastructure, Lifestyle and Community Competence, Economic Development, and Social- Cultural Capital. The PEOPLES Resilience Framework provides the foundation to integrate any quantitative and qualitative models that measures systems' resilience against extreme events (or disasters for that matter) in any or a combination of the above-mentioned seven dimensions. Besides a short-term gap finding analysis, this framework enables communities over the long-term to add and utilize geospatial and temporal decision-support tools that help communities in their planning efforts to assess and to enhance resilienc

Immediate Seismic Resilience of a Controlled Cable-Stayed Bridge

Resilience issues have multidisciplinary relevance and, in recent years, attracted the interest of the scientific community. Within civil engineering sciences, resilience has been often recognized as an attribute of structures with respect to the outcomes of extreme events. Control systems that can adapt to different loading levels can be exploited when structural conditions change due to local failures to offer a contribution to structural resilience. The innovative aspect is related to how the devices features are changed in real time to improve the loss of functionality function, which is at the base of resilience. When the parameters change occurs in real time, on line with the occurrence of a local failure, the concept has been formerly presented in the existing literature as “immediate resilience”, along with a new measure index of resilience. Immediate resilience theory is herein reviewed and underlined with reference to a new seismic case study, coming from a control benchmark, for which strategies for recovering after a damaging event the initial performance of the controlled bridge are presented

Health monitoring of a smart base isolated benchmark cable-stayed bridge using symptom approach

This paper presents a smart base isolation system for cable-stayed bridges, which consists of passive hysteretic devices between the deck and the piers. The ASCE benchmark cable-stayed bridge is used as case study and a more accurate model in ANSYS with nonlinear geometries, cables refinement and soilstructure interaction capabilities is used for comparison purpose. The monitoring of the bridge is approached in the symptom space, assuming that the bridge degrades and deteriorates with time. The damage to the longitudinal isolators between the deck and the pier is considered. It consists in 42 observations throughout the life span of the bridge. Excitation is applied in the time domain in the form of traffic load. This is simulated as translating white-noise load intensity fields. The symptoms considered in the case studies are vibration related parameters and displacement measures at selected position along the deck. Symptoms are ordered in a rectangular symptom observation matrix (SOM) opportunely normalized. By successive application of single value decomposition, it is possible to pass from multidimensional non-orthogonal symptom space to orthogonal generalized fault space, of much reduced dimensions. These information are useful for redesign of conditional monitoring systems