Earthquake Measurements

 Asia is being hit by earthquakes.  This is just standard random clustering, and has nothing to do with fantasy things.  If we want to stick to the Scientific Method, then we need measurements consistent with physics.  Unfortunately, earthquake engineering, codes and siting are stuck in a 'traditional' fantasy land.  We increasingly see the results.  The SM and physics are harsh mistresses, and destroy power structures.  That is why you never see it in action.

A fantasy or groupthink is maintained by those who's power depends on it.  Weather prediction depends on horrible assumptions that are against physics.  They believe that wind drives the ocean currents, and the weather people do not conduct the required experiments.  They also ignore clear-air convection in the atmosphere, which give us the ridiculous assumption that convective air acts as a greenhouse glass.

But the worst for killing people is the earthquake assumption that everything scales on peak acceleration (PGA).  Acceleration for damage scaling has no physics since the PGA goes up dramatically with increasing frequency.  PGA has no physics and should be dropped like a hot potato, yet we will see increasing death counts because of this.

Measurements in Taiwan show that damage is associated with PGV (peak ground velocity), pure and simple.  Don't look at anything else.  I have modelled seismic waves, and pgv scales with the stress (energy) in the wave.  The waves hit the buildings and apply base shear.  The building takes a hit with the first velocity pulse, but may take a while to fall down.  The seismic waves near the earthquake source are always a huge velocity pulse.

The extension to this is that there is no measured or noted effect of building vibration.  This was postulated a long time ago by a single earthquake, and is the entire basis of the shake-table industry.  Can you imagine them admitting they are useless?  Not going to happen.

The big corruption that has hit the phils is this dependence on pga and the fact that deep basins filter out the high frequencies which lowers the pga.  The basins amplify pgv by a factor of 10.  

Thus, we had the ridiculous assertion that your soft building is fine on a jelly-belly basin, when, in fact the opposite is true.

In phil, you would see the pgv on the rock at 2 cm/s, and no damage.  In the basins, it was 20 cm/s with extensive death.  Poor people.

For basins, you need stiff buildings on piles.  This was proven in Christchurch.  You could cut some of the steel in the concrete, and put it into the screw piles budget.

It is in the cards that phil will be hit by another earthquake while the buildings are softened.  That's just odds, even though I feel strongly that a mechanism is being set up.  However, no measurements means no physics.  In my gut, another equivalent pgv will take place in the next month.

ps In Toronto, we will be killed by the same bad assumption of pga and building response.  That doesn't do anything.  We have the Hamilton fault, all lubed and greased up, and in the top 10 for North America.  Totally ignored.  All our condos are 'soft story' bottoms to make room for stores, and the tower is 'floating' on a transfer slab.   All is perfect with shake table tests.  I am not going on with the obvious conclusion here.  So, you are not alone, phil-buddies who buy me coffee.

ps do you notice how fuzzy I am on many statements?  That's called Engineering Design.