Easier, Cheaper, Stronger Brace of Buildings under Earthquake Loads
Submitted by RTFVerterra on Wed, 04/22/2009 - 21:04
A D V E R T I S E M E N T
In response of today’s economic crisis, experts are searching for more economical yet more durable means of construction materials and methods. Funded by National Science Foundation under the Network for Earthquake Engineering Simulation Program, a research was conducted by professors of University of Michigan to test their new technique for constructing high-rise reinforced concrete buildings. A team led by Professor James K. Wight and Associate Professor Gustavo Parra-Montesinos, developed a new way of bracing high rise building to withstand a drift of up to 3 percent during earthquake. The study will allow skyscrapers to withstand lateral deformation than an earthquake would demand.
James K. Wight, Ph.D., PE (left) and Gustavo J. Parra-Montesinos, Ph.D. (right)
During the test, cyclical lateral displacements were applied to a maximum drift that is beyond the safety limit and approximately at the “collapse prevention” limit state. The magnitude of earthquake simulation is as shown in the graph below.
Degree of stiffness, strength retention, energy dissipation, and interstory drift levels are the quantities that were measured during the test. Comparison was made to test results in "original" and "repaired" conditions of the specimen.
For detailed information about the research, click here.
Source: http://cee.engin.umich.edu/node/146
A D V E R T I S E M E N T
In response of today’s economic crisis, experts are searching for more economical yet more durable means of construction materials and methods. Funded by National Science Foundation under the Network for Earthquake Engineering Simulation Program, a research was conducted by professors of University of Michigan to test their new technique for constructing high-rise reinforced concrete buildings. A team led by Professor James K. Wight and Associate Professor Gustavo Parra-Montesinos, developed a new way of bracing high rise building to withstand a drift of up to 3 percent during earthquake. The study will allow skyscrapers to withstand lateral deformation than an earthquake would demand.
James K. Wight, Ph.D., PE (left) and Gustavo J. Parra-Montesinos, Ph.D. (right)
The Experiment
The team used steel fiber-reinforced concrete to develop a coupling beam that is easy to construct, cost effective, and requires less reinforcement. Coupling beams are widely used in high rise buildings to connect openings of shear walls such as doors windows and elevators.During the test, cyclical lateral displacements were applied to a maximum drift that is beyond the safety limit and approximately at the “collapse prevention” limit state. The magnitude of earthquake simulation is as shown in the graph below.
Degree of stiffness, strength retention, energy dissipation, and interstory drift levels are the quantities that were measured during the test. Comparison was made to test results in "original" and "repaired" conditions of the specimen.
For detailed information about the research, click here.
The Result
Coupling beams, though efficient are difficult to install; it requires complex reinforcing bar configurations. The study resulted to a simpler configuration of reinforcement by using a flowable steel fiber-reinforcement concrete. Burdensome reinforcement were removed and replaced by steel fibers during the mixture of the concrete. If crack do occur, it is narrower because the steel fibers hold the concrete together. Most of all, this new technique is cheaper, easier, and more flexible way of providing lateral strength to buildings in earthquake-prone areas. It is now undergoing implementation to high rise buildings under construction on the west cost. Speculations says that this study will put to rest the fear of skyscrapers to tumble down during major earthquakes.Source: http://cee.engin.umich.edu/node/146
- ‹ previous
- 10 of 13
- next ›
- RTFVerterra's blog
- 1709 reads
-
Post new comment