Nevada quake lab tests new bridge design after Mexico quake Graduate students at the University of Nevada, Reno's College of Engineering inspect a bridge model for damage after tests on a giant shake table intended to simulate violent earthquake activity at the school's new Earthquake Engineering Building in Reno, Nev., Wednesday, Sept. 20, 2017. (AP Photo/Scott Sonner)
Nevada quake lab tests new bridge design after Mexico quake
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Scientists at a Nevada earthquake lab tested new bridge designs. This happened last Wednesday. The designs have connectors they say are innovative. The designs were created to better withstand violent temblors. The designs are also intended to speed reconstruction after major quake damage.

University of Nevada, Reno engineers performed the experiments. They did so on a giant "shake table." They attempted to simulate violent motions of an earthquake. They wanted to rattle a large bridge model. They wanted to see how well it would hold up.

The tests were conducted a day after a big quake struck Mexico. That quake shook large concrete columns and beams back and forth for about 30 seconds at a time. It displaced some nearly a foot. This was before they mostly returned to their original spot.

Graduate students measured and marked indications of tiny fractures. But no major structural damage was observed. This was in the initial review of the experiments.

"The bridge has done better than we expected," said Saiid Saiidi. He is a professor of civil and environmental engineering. He served as the project leader. He's done related research for more than 30 years.

Bridges are already designed not to collapse in earthquakes. But they are often unsafe for travel after big quakes. He said the designs that were tested used special types of connectors. They linked pre-made bridge parts. This included ultra-high performance concrete.

"Earthquakes by themselves don't kill people. It's the structures," Saiidi said.

The elements have been tested on their own. But they were never tested before combined in a bridge model subjected to realistic earthquake motions, like the 1994 Northridge, California quake. Wednesday's test simulated activity of a quake. It was as large as magnitude 7.5.

Some design work by the engineers has been incorporated into a highway off-ramp. It is under construction. It is in Seattle. It's the first bridge in the world that uses flexible columns. It also uses reinforcement bars. They are made out of a metal alloy with titanium. They bend and then springs back into shape when quakes hit.

The innovative connectors allow for pre-made concrete and other materials to be attached to an existing bridge foundation. This should speed repair. It should also speed reconstruction.

Part of the research centers on a so-called "pipe pin" connection. It was developed by the California Department of Transportation's bridge designer. They intend to use it for connecting certain beam interfaces in bridge construction.

The pin consists of a steel pipe. It is anchored in the column. It is extended into a steel can embedded in the beam. A gap between the steel pipe and the can enables the extended segment to freely rotate inside the steel can. This prevents bending of the protruded segment inside the can.

The University of Nevada's Earthquake Engineering Lab is the largest of its kind in the United States.

The latest project is funded by the California Department of Transportation. It is developing plans for 10 pilot projects. The projects are based on the developing bridge connector technology.

"This study today is going to allow them to make observations of those designs," Saiidi said.

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CRITICAL THINKING QUESTION
Why does Nevada care about Mexico?
Write your answers in the comments section below


COMMENTS (45)
  • coreyd-hol
    10/06/2017 - 09:53 a.m.

    They would like to help stop the damage of major earthquakes in the United States. They are also trying to make to reconstruction of buildings faster and easier.

  • matthewb-hol1
    10/06/2017 - 09:55 a.m.

    Because they are close to mexico and if the same thing happens to them they need to be prepared

  • davidc-hol2
    10/06/2017 - 09:57 a.m.

    The tests were conducted a day after a big quake struck Mexico. Graduate students measured and marked indications of tiny fractures. But no major structural damage was observed. Some design work by the engineers has been incorporated into a highway off-ramp. It is under construction. It is in Seattle. It's the first bridge in the world that uses flexible columns.

  • victoriai-hol
    10/06/2017 - 09:57 a.m.

    Nevada cares about Mexico because they want to help prevent more bridge collapses and to learn more about earthquakes so they can learn how to make structures safer for all.

  • paigeg-hol
    10/06/2017 - 09:58 a.m.

    Nevada cares about Mexico because they are close together and they care about what happens so making these bridges will help save a lot of time and money when earthquakes happen.

  • hansg-hol
    10/06/2017 - 09:58 a.m.

    Nevada cares about Mexico because the designs for structures and bridges they come up with can be safer after a quake and stronger before and after it. They want to share this tech with others to help them.

  • kendalm-hol
    10/06/2017 - 09:58 a.m.

    Nevada cares about Mexico because they want to help with there earthquakes. Nevada's Earthquake Engineering Lab is the largest of its kinda in the United States.

  • hannahh-hol1
    10/06/2017 - 09:59 a.m.

    Nevada cares about Mexico because there are innocent people in Mexico that need help with their collapsed bridges from earthquakes. The Nevada earthquake scientists are making new bridge designs to prevent the structures from falling.

  • bradenb-hol1
    10/06/2017 - 09:59 a.m.

    I think Nevada cares about Mexico because if an big earthquake struck here in the Us,Mexico would help like we helped them. Another reason i think Nevada is helping them is so they can prevent lives being lost.

  • zanes-hol
    10/06/2017 - 10:00 a.m.

    there was a big quake that happened in mexico

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