If the piles were driven into the ground, you should look into the possibility of the pile joints being broken during the driving process. We had several piles broken this way while driving through a hard soil layer into a softer layer. The large vibrations induced during the driving process...
DMG Special Publication 117 and the Recommended Procedure for Implementation of DMG Special Publication 117, recommends using a seismic screen analysis for determination of the seismic coefficent for slope stability analyses. We have found that the screen procedure yields seismic coefficents on...