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Showing posts from May, 2016

Earthquake vs Energy Dissipation

In this blog post, I will try to explain in simplest words possible as to what happens to a building during an earthquake. 
Imagine this: You are travelling in a car which I am driving. I applied a sudden brake. You will experience a serious "jerk" and most probably curse me after that. But that sudden "jerk" also called as deceleration is experienced because your body changed the velocity from 100 feet/second to dead zero in 3 seconds. That is equivalent to gravitational acceleration applied in horizontal direction. This is called inertial force. There was a change in state of motion of your body. 
"A body at rest stays at rest and a body in motion stays in motion unless an external force is applied to change the state of body" - Newton's first law of motion. 
A force experienced by a body is equal to:
Force = Mass x Acceleration
When earth shakes, it gives these impulses at the base of the building. Let us look at an acceleration time history. (A r…