‘Limb-inspired’ Bridge Design Holds up to Earthquakes Better
Earthquakes can result in severe damage to bridges and other structures. In addition to the risk to lives, the repair cost can also be catastrophic. But a new ‘limb-inspired’ bridge design may hold up better to earthquakes, and result in much less expensive repairs when needed.
The new bridge designs come from a team of engineers and researchers at Texas A&M University and the University of Colorado Boulder. The National Science Foundation (NSF) provided funding for the research.
Their designs appear to result in a structure that is more damage-resistant. Less damage could mean saving billions in repair costs after a large earthquake.
So far, these designs have been limited to the lab, and are still in the early stages of development, but appear promising.
The design is based on how limbs and joints in the body work to support us while also absorbing impact and allowing for some flexibility.
Current bridge designs will crack and even break when subjected to very large quakes. They are constructed of steel and poured re-enforced concrete. There is no flexibility in these structures.
They are built to support their own weight plus expected traffic loads. But they are static structures built on a stationary surface. The problems come when the surface is no longer stationary – like with an earthquake.
The team calls their design a hybrid sliding-rocking bridge. During an earthquake, “the joints allow some of the energy from the ground motion to spread while the segments move slightly, sliding over one another rather than bending or cracking,” explains the NSF in a press release on the design.
When the team compared their ‘limb-inspired’ bridge design to current designs when subjected to a quake, the results were dramatic.
The columns in the new design “showed very little damage even when subject to motions reminiscent of a powerful once-in-a-few-thousand-years earthquake.”
What’s more, the damage that did occur could be repaired easily and inexpensively. The complete detailed of the study were published in the Journal of Structural Engineering.
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