Earthquakes are among the world’s deadliest events, and one of the reasons they cause so much destruction is that the buildings in quake-struck areas can’t handle the resultant stress.
A team of researchers representing the University of Arizona, Lehigh University, and the University of California, San Diego, is investigating improvements that could help buildings stay standing when these natural disasters strike.
Understanding the Structural Forces Caused by Earthquakes
Various forces affect buildings during an earthquake. For example, an inertia force happens when the ground moves under a building, and it goes backward. The inertia force hits the roof and causes vibrations, and the columns at the edges of a building transfer the energy from the inertia force to the ground.
The power of the inertia force rises with the building’s mass, so lighter buildings can tolerate an earthquake’s shaking better than heavier ones. In addition, lateral forces make buildings sway.
Taking a Different Approach to Structural Safety
People seeking to enhance the safety of structures in earthquake-prone areas typically focus on the vertical transfer of forces and the parts of buildings such as the walls and braces.
However, the researchers in this study are looking at the horizontal transfer of forces made possible with reinforcements in a building’s flooring known as steel collectors.
Located either inside concrete floor slabs or in beams below it, the collectors facilitate horizontal energy transfer during an earthquake. Engineers working on projects that help buildings sustain earthquakes put networks of structural fuses inside a building’s framework or walls.
The steel collectors transfer energy horizontally from the floor to the walls, allowing it to reach the fuses, as long as the collectors are strong enough to handle the forces.
Companies that provide specialty steel for clients know numerous specifics could affect the worthiness of the material for an intended purpose. For example, how metal is cut should play a role in determining its use.
The researchers’ project, which is officially titled “Advancing Knowledge on the Performance of Seismic Collectors in Steel Building Structures,” will do something similar by looking at components made from steel and improving how they help buildings tolerate earthquake forces.
Simulating the Variables of a Shake Table Test
Part of the scientists’ work involves testing model structures on a shake table, which has a platform moved by pressurized oil.
Because a shake table test with an actual structure costs hundreds of thousands of dollars, the researchers rely on computerized simulations to figure out the ideal model for a shake table test.
Anshul Agarwal, one of the project’s doctoral students, runs more than four dozen simulations daily. That task requires tweaking variables including the height of the building and the size of its beams.
When it’s time to do a shake test outside the realm of a computer, the results either confirm the models’ usefulness or show it’s necessary to make further adjustments before they work as expected. In any case, the data collected from a shake table test helps the team plan future actions.
How Could This Work Help the World?
Common wisdom says it’s not earthquakes that kill people, but the buildings that fall due to the disasters.
People are often dismayed how most of the world’s buildings still aren’t earthquake-proof — despite many recent advances affecting society at large being so impressive they seem straight out of a science-fiction novel.
There are multiple challenges to overcome regarding making buildings stand firm against seismic activity, such as the fact that even the most advanced shake tables can’t account for all the types of motion an earthquake could cause or the ways those structures interact with the soil underneath them.
The lack of available funding is also problematic and often restricts researchers by resigning them to work on small projects that might only impact a small component of a building. In August 2017, though, the work mentioned above got a grant of approximately $800,000 from the National Science Foundation.
Depending on the outcome of that multi-university project, the people working on it may engineer ways to make buildings resilient against earthquakes during the construction process, plus come up with ways to retrofit older buildings designed by people who didn’t have those catastrophes in mind.
Recent earthquakes have caused hundreds of thousands of fatalities. In addition to reducing the loss of human life, advancements that make buildings stay up during these disasters should positively affect the loss of productivity and substantial cleanup processes often triggered by these events.
The team profiled above is also well-equipped to overcome challenges, particularly since the researchers teamed up twice before and achieved award-winning results, as well as convinced federal authorities to alter building codes.
As their work progresses, it’ll be fascinating to see if their dedication translates to life-changing improvements that impact people around the globe.
Written by Kayla Matthews, Productivity Bytes.