Sunday, April 7, 2024

Taiwan earthquake explanations - Part 2

 Continued from this article.

That article had other muck in it.  This continues with the explanation of terms.

The Taiwan earthquake is being pushed by influencers as a great success, when in fact it was a total engineering failure, much like that US bridge collapse.  I'm being obscure, so as to not attract nasty influencers, as if they read anything.

The buildings were designed for peak acceleration, whereas the failure was peak velocity.

This was 'seismic fling', as explained by many papers.  The papers seem hung up on a permanent displacement, but the main characteristic is a velocity pulse.  

A long time ago, all earthquake engineering started with California, since they were the first to record strong ground motion.  At the time, all their damaging earthquakes were on deep soft soil basins, so their world view was contaminated by this.

They effectively set up a hypothesis, which became a religion, and the base of their existence. ---

All damaging earthquakes in the world are a result of deep soil motions, and are scaled by peak acceleration, and the mechanism of damage is seismic resonance.

That means you design for resonance (response spectrum) and the scaling factor is peak acceleration.  Thus, the rise of shake tables.

- to be continued

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