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.
Hugo Cerdà | alfa
Concrete from wood
05.07.2017 | Schweizerischer Nationalfonds SNF
Modular storage tank for tight spaces
16.03.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
18.08.2017 | Life Sciences
18.08.2017 | Physics and Astronomy
18.08.2017 | Materials Sciences