Earthquake Resistance Techniques
Outline
I. Introduction
A. There are three common earthquake resistant building structure techniques
1. Base Isolation
2. Energy Dissipation devices
3. Active Control Devices
B. Out of the three is base isolation technique the best for earthquake resistant buildings?
1. Rolling pads that move
2. The ground will shake, building will stay in place
Thesis statement: Base Isolation is the best technique Than othersfor earthquake resistant buildings.For the efficient,and The cost
Body:
*Active Control devices its control the extra energy of the earhquakes
1. Widely used in aerospace structures
2. Watches for the structures response to the earthquakes and have control against the earthquake.
3. Analysis
a. Still a work in progress
Might be better than Base Isolation after the researcher and experiences
According to the author.The active control can reduced the wave of earthquake to 6%.When we installed inside the building(Active Control Devices for Earthquake Resistance,2011).
As you see It has a good advantages its provide the building with strength and rigidity,but other techniques are more efficient and better.
In concluding it could be the new generation of earthquakes but it has more disadvantages than the other two techniques
**Energy dissipation devices
1. Diagonal braces with dampers absorb the shock from the earthquake
2. Like a car, it absorbs the shock and decreases the motion of the building
3. Analysis
More expensive than Base Isolation
Too much maintenance and fluid for one piston.
According to the author.When we install this devices we have less damage during an earthquake(Energy Dissipation Devices for Earthquake Resistant Building Design,2011)
As we see Energy d...
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Earthquake Resistant Structures. (n.d.). Earthquake Resistant Structures RSS. Retrieved November 14, 2013, from http://articles.architectjaved.com/earthquake_resistant_structures/active-control-devices-for-earthquake-resistance/
(1995). Response of high-rise and base-isolated buildings to a hypothetical mw 7.0 blind thrust earthquake. Retrieved from
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Heller, Arnie. "The 1906 San Francisco Earthquake." Science & Technology (2006): 4-12. Web. 8 May 2014.
From studying the science behind the San Francisco earthquake, scientists have made a number of important discoveries involving how earthquakes function. At 5:12 on a fateful April morning in 1906, the mammoth Pacific and North American plates sheared each other at an incredible twenty-one feet along the San Andreas fault, surpassing the annual average of two inches (“San Francisco Earthquake of 1906”) (“The Great 1906 Earthquake and Fires”). A few seconds later, the destructive earthquake occurred. The ground shifted at almost five feet per second, and the shaking could be felt all the way from southern Oregon to southern Los Angeles to central Nevada (“Quick”) (“The Great 1906 San Francisco Earthquake”). In fact, the earthquake could be registered in a seismograph on Capetown, South Africa, an astounding 10,236 miles away...
Stringent seismic criteria related to construction in the San Diego area made it difficult for Kahn's structural engineer to convince local building officials, who wanted him to use steel frame, that concrete, Vierendeel truss system would have the required flexibility. They agreed only after a 400 page report of undoubtedly integrated deflection computations that shows how post-tensioned columns would provide the main resistance to lateral seismic forces. These columns absorb both dead and live load compression plus vertical post-tensioning forces. They were also designed to maintain zero tension if subjected to lateral movements by earthquake. The trusses are 9 ft deep, spaced 20 ft on center and have a clear span of 65 ft (diagram 2). He made use of the 9 ft high resultant space as service area, allowing pipe chases to be dropped to the 65x 245 ft floor below with more latitude than before.
Due to the hazard that earthquakes cause, a hazard consultant becomes a critical part of
The Physical and Human Factors Which Affect the Location and the Impact of the Earthquake Hazard
Unfortunately, as the San Francisco Chronicle in 2006 reported that “there are still thousands of hostility rebuilt, unreinforced masonry buildings” that are build very close together with no fire resistance walls in between (John Galvin, 2007). Plus, the Association of Bay Area Governments stated that if a magnitude 7 and above earthquake a long the San Andreas Fault by San Francisco will affect the homes of many thousands of people forcing them to live in the streets once again (John Galvin, 2008). In the other hand, according to John Galvin article San Francisco’s water delivery system was improved and even though insurance companies loss a lot of money they paid out millions in claims.
Today, engineers rely on damping systems to counteract nature's forces. There are many types of damping systems that engineers can now use for structures, automobiles, and even tennis rackets! This site focuses on damping systems in structures, mainly architectural variations of the tuned mass damper.
Earthquake’s can be very destructive in many ways. “Collapsing buildings claim by far the majority of lives, but the destruction is often compounded by mud slides, fires, floods, or tsunamis”(National Geographic par.3). They can kill one person up to one hundred thousand people. Loss of life can be avoided through emergency planning, education, and the construction of buildings that sway rather than break under the stress of an earthquake.
The failure of beam-to-column connections in steel Special Moment Resisting Frames had the most to do with most of the damage in these buildings. In response to the pattern of buildings including SMRF's, there have been studies to improve the design and construction practices to allow for better and more improved buildings. The higher building codes wanted engineers to find new ways to allow homes, apartments or skyscrapers the ability to sustain a powerful earthquake. These engineers borrowed the model from New Zealand engineer Bill Robinson. His method was to use lead-rubber bearings, which minimize the vibrations caused by the earthquake, improving its performance during seismic activity. Many of the old buildings that took damage during the earthquake had to be retrofitted. This was done by either infilling the walls, adding braces, adding buttresses, adding new frames, exterior or interior, completely rebuilding or isolating the building. All of these techniques of retrofitting a building all add extra support to the remainder of the building. Most of the residential structures that took damage and were deemed uninhabitable were the apartments or condominiums that were made of light, wood frames. Also, many houses made using stucco took extensive damages. This was due to the fact that the stucco was not properly installed in the first place,
Part A: Structural Safety Part B: Fire Safety Part C: Resistance to contaminants and moisture
Both types of dampers belong to the category of passive supplemental damping devices. These devices can be used either for new building or for retrofitting purposes of existing buildings. Dampers act by dissipating seismic energy and can significantly decrease the response of structural frame buildings subjected to earthquakes. Building drifts and member forces are substantially reduced by adding damping to the structure and thus both structural and non-structural components are protected. Viscoelastic dampers also add stiffness to the structure.
Taher, R. (2011). General recommendations for improved building practices in earthquake and hurricane prone areas. San Francisco, CA: Architecture for Humanity Retrieved from
The benefits of an outrigger system lies in the fact that building deformations resulting from the overturning moments get reduced, on the other hand greater efficiency is achieved in resisting forces. Outrigger engages the perimeter columns in lateral load resisting action which would otherwise acts as a gravity load resisting elements.
Earthquakes belong to the class of most disastrous natural hazards. They result in unexpected and tremendous earth movements. These movements results from dissemination of an enormous amount of intense energy in form of seismic waves which are detected by use of seismograms. The impact of earthquakes leaves behind several landmarks including: destruction of property, extensive disruption of services like sewer and water lines, loss of life, and causes instability in both economic and social components of the affected nation (Webcache 2).
It ensures that there is prevention of undue deterioration of building facilities and thereby preserving the buildings investment capital, functionality and,