New building design withstands earthquake simulation (Video)

Feb 26, 2009
Engineers constructed a four-story, 40-percent replica of a building in a laboratory to test their new technique for bracing high rise buildings in earthquake zones. They simulated an earthquake by pushing and pulling the building with hydraulics. Image: Remy Lequesne

(PhysOrg.com) -- Researchers at the University of Michigan simulated an off-the-charts earthquake in a laboratory to test their new technique for bracing high-rise concrete buildings. Their technique passed the test, withstanding more movement than an earthquake would typically demand.

The engineers used steel fiber-reinforced concrete to develop a better kind of coupling beam that requires less reinforcement and is easier to construct. Coupling beams connect the walls of high rises around openings such as those for doorways, windows, and elevator shafts. These necessary openings can weaken walls.

"We simulated an earthquake that is beyond the range of the maximum credible earthquake and our test was very successful. Our fiber-reinforced concrete beams behaved as well as we expected they would, which is better than the beams in use today," said James Wight, the Frank E. Richart Jr. Collegiate Professor in the U-M Department of Civil and Environmental Engineering.

This video is not supported by your browser at this time.
Engineers at the University of Michigan simulated an off-the-charts earthquake in a laboratory in December to test the strength of their new technique for bracing high-rise buildings.

Working with Wight on this project are Gustavo Parra-Montesinos, an associate professor in the Department of Civil and Environmental Engineering, and Remy Lequesne, a doctoral student in the same department.

Today, coupling beams are difficult to install and require intricate reinforcing bar skeletons. The U-M engineers created a simpler version made of a highly flowable, steel fiber-reinforced concrete.

"We took quite a bit of the cumbersome reinforcement out of the design and replaced it with steel fibers that can be added to the concrete while it's being mixed," Parra-Montesinos said. "Builders could use this fiber-reinforced concrete to build coupling beams that don't require as much reinforcement."

The engineers envision that their brand of beam would be cast off the construction site and then delivered. Nowadays, builders construct the beams, steel skeletons and all, bit by bit as they're building skyscrapers.

Their fiber-reinforced concrete has other benefits as well.

"The cracks that do occur are narrower because the fibers hold them together," Parra-Montesinos said.

The fibers are about one inch long and about the width of a needle.

The engineers performed their test in December on a 40-percent replica of a 4-story building wall that they built in the Structures Laboratory. They applied a peak load of 300,000 pounds against the building, pushing and pulling it with hydraulic actuators.

To quantify the results, they measured the building's drift, which is the motion at the top of the building compared with the motion at the base. In a large earthquake, a building might sustain a drift of 1 to 2 percent. The U-M structure easily withstood a drift of 3 percent.

The new beams could provide an easier, cheaper, stronger way to brace buildings in earthquake-prone areas.

The researchers are now working with a structural design firm to install the beams in several high rises soon to be under construction on the west coast.

Provided by University of Michigan

Explore further: FAA's Airworthiness Directive issued to avoid power loss

Related Stories

New research provides clues about honey bee decline

58 minutes ago

A new study by Heather Mattila, a leading honey bee ecologist and Assistant Professor of Biological Sciences at Wellesley College, published this April in PLOS ONE, reveals that inadequate access to pollen ...

Recommended for you

FAA's Airworthiness Directive issued to avoid power loss

May 02, 2015

A fix for a software problem that could possibly result in power loss in Boeing 787s has been ordered. Federal Aviation Administration officials adopted a new airworthiness directive (AD), effective as of ...

Recycling aluminium, one can at a time

May 01, 2015

Producing pure aluminium from ore accounts for as much as 1 per cent of all greenhouse gas emissions worldwide. Recycling is the best way to reduce that carbon footprint – but manufacturers and recycling ...

Bringing hypersonic flight closer to reality

May 01, 2015

Two University of Sydney aeronauticalengineering PhD researchers have been invited by the European Space Agency (ESA) to help realise the dream of travelling across the globe at 7 times the speed of sound.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

WolfAtTheDoor
not rated yet Feb 26, 2009
That's great, but it's kind of a small building.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.