Earthquakes, explosions, impacts and blast threaten the safety of buildings, construction works and infrastructure. Large-scale testing and numerical simulation are complementary tools to study the effects of such events on the built environment and develop appropriate design methods, with a view to reducing the consequencies in terms of casualties, economic loss related to physical damage and disruption of essential services. Standards have also an important role in harmonising safety levels within the European Union and in providing a common technical language based on the most recent scientific and technological developments.
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Testing for increased seismic safety
It is unfortunately not possible to predict the location and intensity of future earthquakes, but most of the human casualties are due to the collapse of inadequate construction. Therefore, effective prevention has to be based mainly on adequate design, construction and maintenance of civil engineering structures. To mitigate the effects of earthquakes, the JRC studies the structural behaviour of buildings and other infrastructures under earthquake scenarios, develops methodologies to increase the safety of buildings and contributes to the creation of European standards for the construction sector.
More information: European Laboratory for Structural Assessment
The European Laboratory for Structural Assessment (ELSA) of the JRC is equipped with one of the three largest reaction walls in the world and the second in capacity. The ELSA reaction wall consists of an extremely stiff vertical wall and a horizontal floor rigidly connected together. The structure to be tested, generally a full-scale building, is fixed to the horizontal floor. Once the 'test structure' is in place, the force that an earthquake would generate is applied through hydraulic jacks acting between the structure and the vertical wall, subjecting the structure to loads equivalent to those caused by an earthquake. For the purposes of testing - so-called 'pseudo-dynamic' testing - the earthquake experiment takes place in extremely slow motion, one to two hours rather than the 10 to 30 seconds duration of a real earthquake, allowing progressive damage and structural deformations to be accurately observed and recorded.
Supporting the development and implementation of standards
The research carried out at the JRC contributes to the development of the Eurocodes, a set of European standards for the design of buildings and other civil engineering works. Since 2010 the Eurocodes have reached the final stage of national implementation by the Member States as they are now replacing all national standards, assuring more uniform safety levels for buildings and critical infrastructures within the EU. The JRC has contributed significantly in bringing the Eurocodes to their present stage and is now supporting their implementation, harmonization and further development.
More information: Standards in construction: the Eurocodes
Protecting buildings from explosions, impacts and blasts
Built infrastructure, such as government buildings, dams, power plants, train stations, are potential targets for terrorist threat and can also be damaged by accidents. Their protection starts from the resistance and robustness of the physical structure itself, so that if security measures fail, catastrophic consequences can be contained. The JRC works on the physical protection of critical infrastructures under certain types of intentional threats or accidents, such as explosions, impacts and blast waves. Vulnerabilities of buildings are identified and classified via proper material modelling, structural mechanics and numerical simulation techniques.
Specific security measures like intelligence collection and analysis, surveillance, monitoring and detection of threats are always required to protect critical infrastructures. However, should a breach of security occur and all precautionary measures fail, the physical structure itself will bear the first consequences of an attack. By choosing the right materials and designing the structures so that they can resist abnormal loads, such as explosion and impact, it is possible to avoid or mitigate major disasters involving injuries due to flying debris, fatalities due to progressive collapse etc..
The JRC develops numerical simulations and experimental tools for assessing the robustness and resilience of building structures to impact and explosion loads and avoiding the progressive collapse, which could be a failure disproportionate to the initial cause. The JRC also develops simulation methodologies for the vulnerability assessment of transport infrastructures, in particular of railway stations and rolling stock, to bomb explosions and for predicting structural response and shock wave effects to the surrounding area and humans. Structural security assessment in energy infrastructures, such as dams or nuclear installations, is also carried out by investigating the mechanical behaviour of construction materials. JRC's research work contributes also to the harmonisation of the physical protection of public buildings and critical transport and energy infrastructures in the Union.
Improving safety of precast structures
The JRC participates in the FP7 project SAFECLADDING which addresses the problem of the interaction of cladding elements with the precast structures. The role of the JRC is to provide the full-scale experiments, to be conducted on a realistic portion of a single-storey building, equipped with a series of different arrangements of claddings and fixture devices.
More information: SAFECLADDING - Improved fastening systems of cladding panels for precast buildings in seismic zones
Mitigating seismic risk in lead-cooled nuclear reactors
The JRC is a partner of the FP7 project SILER, which is specifically dedicated to the seismic isolation of generation IV lead-cooled nuclear reactors. Within this project, the JRC role is to perform the full-scale seismic testing of an expansion joint prototype destined to equip the pipes carrying fluids at high temperature and pressure across the seismic gap between the isolated and non-isolated parts of the nuclear power plant.
More information: SILER - Seismic initiated events risk mitigation in lead-cooled reactors
Stress tests of critical infrastructures
Critical infrastructures provide essential goods and services for modern society; they are highly integrated and have growing mutual dependencies. To reduce the societal and economic consequences of low probability-high consequence events, the FP7 project STREST aims at designing a stress test framework that addresses the interdependencies and vulnerability of critical infrastructures. The JRC is leading the dissemination activities and the interaction with stakeholders.
More information: STREST - Harmonized approach to stress tests for critical infrastructures against natural hazards