Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bridges equipped with dampers against earthquakes

08.09.2005


Researchers at the Universitat Jaume I of Castelló and at the University of California have devised a system to reduce the damage caused by earthquakes in bridges. Installed between the piers of a bridge and their respective foundations, it is a flexible device that helps to mitigate the effects produced by the movement of the Earth’s surface, working in a similar way to the shock absorbers in cars. The study has been published in the journal Earthquake Engineering and Structural Dynamics.

Because of the horizontal accelerations brought about by earthquakes, the bridge deck is subject to displacements and forces that could damage its structure. To avoid this, a new type of damper whose stiffness and damping features adjust to the deck position at each moment is introduced, absorbing the energy introduced into the structure by the earthquake and therefore reducing the structural damage. To date, similar damping systems have been designed, but the novelty introduced by the one developed by the Universitat Jaume I and the University of California is that, as the earthquake takes places, the bridge piers do not move freely. Instead, the devices incorporated cause a swaying type of movement of the bridge deck, which is very stable under seismic conditions. This is possible because the dampers very easily show an increase in length but offer high resistance to compression. Then, as the bridge sways sideways, one leg stretches while the other bears the weight of the bridge, and when the movement changes direction, the opposite happens.

“We are thinking about an A-shaped frame with two legs. When the ground motion starts to take place horizontally from left to right, what happens is that one of the piers forming the A elongates and all the weight of the bridge is transferred to the other one. In the commercial systems that are usually installed, the spring of this second pier yields and is compressed, that is, the spring is compressed as easily as it is stretched. What we have proposed here is that piers can stretch but offer great resistance to compression, thus significantly reducing motion at the bridge deck, as we have proved with virtual simulations”, explains M. Dolores Martínez Rodrigo, a lecturer at the Department of Technology at the Universitat Jaume I of Castelló.



One of the most striking conclusions of the study, according to scientists, is that with this damping system it does not matter how high the ground acceleration is during the earthquake, as the bridge motion velocity is always kept within safe limits.

“This system yields two immediate results: on the one hand, lateral acceleration is limited as if the bridge were an inverted pendulum and, on the other hand, the point of support of the superstructure rises and thus kinetic energy is systematically transformed into potential energy. At the end of the earthquake, the system is slowly self-centring”, explain the authors of the study, which has been published in Earthquake Engineering and Structural Dynamics.

The researchers have also published the results from the application of this kind of system to conventional buildings, although further research remains to be conducted in this sense.

Hugo Cerdà | alfa
Further information:
http://www.uji.es/ocit

More articles from Architecture and Construction:

nachricht Modular storage tank for tight spaces
16.03.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

nachricht Smart homes will “LISTEN” to your voice
17.01.2017 | EML European Media Laboratory GmbH

All articles from Architecture and Construction >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>