ELSA engineers find out what happens when the earth moves
Engineers from the European Laboratory for Structural Assessment (ELSA) have produced a video, available now on-line, that explains how and why they simulate earthquakes to determine points of weakness in European monuments. They use 'paraseismic construction techniques' to simulate the damage caused to buildings during earthquakes, a risk to which European cities are growing increasingly vulnerable in the face of 'galloping urbanisation', says ELSA. Such research is extremely expensive and only truly viable with international collaboration, according to the Joint Research Centre, of which ELSA is a part. Its laboratory is based on a 16 metre high reaction wall and two strong floor systems. This facility allows static; cyclic (fatigue), and pseudo-dynamic testing of large and full-scale models of structures, such as, for instance, a full-scale four to five storey building or a large bridge. The floor-wall system provides the strength and rigidity necessary to resist the loads that are applied to the test structures using servo-controlled electro-hydraulic actuators. By submitting these models to stresses and strains equivalent to those in action during an earthquake, the scientists can identify rupture points and then reinforce the equivalent sections in the real buildings themselves - without spoiling the original architecture. ELSA is compiling its findings in 'Eurocode 8' a catalogue of recommendations for constructors contributing to safer towns and cities.