Oklahoma DOT workers inspect a bridge after an earthquake. Saiid Saiidi, a professor of civil and environmental engineering at the University. A good bridge has to endure a lot from Mother Nature. In earthquake-prone parts of the globe, that's an especially tall task: even if they survive. SMAs demonstrate an ability to re-center bridge columns, which minimizes the permanent tilt columns can experience after an earthquake. Traditional bridge columns are constructed from concrete and reinforced steel, which are seldom effective against earthquakes.
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SMAs demonstrate an ability to re-center bridge columns, which minimizes the permanent tilt columns can experience after an earthquake.
Traditional bridge columns are constructed from concrete and reinforced steel, which are seldom effective against earthquakes. But new research suggests that replacing concrete and steel with smart materials is a good alternative. While the majority of SMAs are only temperature-sensitive, meaning that they require a heat source to return to their original shape, Nitinol is also superelastic.
This means that it can absorb the stress imposed by an earthquake earthquake resistant bridges return to its original shape, which makes nitinol a particularly earthquake resistant bridges alternative to steel.
Smart Materials Improve Earthquake-Resistant Bridge Design
In fact, the superelasticity of nickel titanium is between 10 to 30 times earthquake resistant bridges elasticity of normal metals like steel. Many of us know nickel titanium from our flexible prescription eyeglass frames.
The material allows frames to easily return to their original shape after being bent in any direction.
To assess the performance of nickel-titanium reinforced concrete bridges, the researchers analyzed three types of bridge columns: To strengthen the concrete and prevent immediate failure in an earthquake, the researchers used the shake tables to test glass and carbon fiber-reinforced polymer composites.
It is proposed to restrain the rigid blocks with an unbonded post-tensioning cable in order to allow rocking but prevent overturning. earthquake resistant bridges
The findings made on rigid blocks, however, cannot be applied to deformable structures because of the limitations of the model. Therefore, a completely different approach is proposed.
Instead of modeling the behavior of an entire earthquake resistant bridges, it is proposed to model only the rocking surface.
A zero-length finite element earthquake resistant bridges developed, allowing to represent the in-plane rocking rotation between two frame elements. It allows to investigate the behavior of a deformable column rocking freely on its base as well as the stability of a rocking column restrained with a cable and subjected to a large earthquake excitation.
The consequences of a post-tensioning cable failure and yielding of the column are also investigated. It is proposed to add a dissipative fuse earthquake resistant bridges the base of the column and its footing in order to enhance the stability of the structure. Finally, the behavior of a conventional monolithic bridge is compared with a bridge allowed to rock at the columns joints.
The tunnel project was suspended IIRC, no surprise. Anyway, I'm just exploring if such a bridge is technically earthquake resistant bridges and can be quake-resistant. I saw here they were working to make it safe in quakes up to 8. And keep in mind the Golden Gate Bridge does not handle freight trains.
Design of Earthquake Resistant Bridges Using Rocking Columns
Anyway, is it possible to quake-proof or seriously resist quakes in large bridges loaded with a earthquake resistant bridges train? The bridge would not necessarily have to remain completely undamaged.
I just don't want it to snap and drop the train in the ocean.