The Sounds of Earthquake Damage

This is a an audio output from a Newmark sliding block analysis. When the ground accelerations exceed .2g there is relative displacement of the "block" or yielding of the structure which I've translated into  sound.  The earthquake starts with a positive 1g pulse, then a negative pulse, then a harmonic motion at 0.6 g.

for a cooler version of this, click here.

What would it be like to be in a building that was near collapse in downtown LA during the 1994 Northridge earthquake? For those who can face reliving it, click here.Wait a few seconds for the audio clip to load.

Here below is the velocity output of the first (artificial) earthquake expressed as a sound frequency; the faster the block is moving the higher frequency (like the nails being pulled out in a house.). The sound below is what you heard when you opened this page.

The structures (or Newmark bases) are rigid in all cases, ie there is no vibratory response. The motion parameters for the first artificial earthquake are shown below.

For a more scientifically-oriented evaluation of the comparative effects of two different earthquakes at the same site, click here.

Dick Meehan
meehan@stanford.edu
 
 

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