Hi Petra - A noble thought indeed.

They do fill cracks around dams with a concrete fill to lessen water leakage and to strengthen the dam itself.

As for stopping quakes... I don't think its really possible given the force of Mother Nature and the tectonic plate movement. To really stop it you would have to cool down the planet so that there is no more molten core to cause the movement. Of course that would also stop the volcanoes and geothermal activities.

What other ramifications would there be from a 'cool earth'? Interesting to speculate.

I think building in alignment with the forces of nature is a much better solution than trying to stop the unstoppable.

Canie