Foundation piles in seismic conditions

[Mccoy]

Any idea or practical experience on the behaviour of piles and pile groups in seismic conditions?
I once heard from a qualified source that piles performance under seismic stress isn't ideal, but did not research the topic further.
What can go wrong? if pile tips lay on the bedrock, and thickness of soft layers is not minimal, sure seismic energy and signal are different at the pile base, along the shaft and at ground level.
And what if liquefaction occurs? can lack of lateral ground support cause significant pile bending?
And, above all, are there valid alternatives to piles or precautionary measure to be used in highly seismic areas?

 

[BigH]

I'll put in a bit on a caution that I have always remembered. In the 1964 Nagata Earthquake a good many pile caps were seriously damaged when they contained battered piles. Apparently, the small arrival time differences along the pile length caused significant moments being set up in the pile cap. Since the 1980s in Vancouver area of Canada, they have designed all piles to be vertical piles with the expectation that the group would ride out the transverse displacements as a unit without the problems noted in Nagata. Reference, I believe, was a late 60's or early 70s paper in the ASCE Geo Journal (then the Soil Mechanics Journal).