This short video demonstrates the influence of earthquakes and liquefaction on the stability of foundations. A liquefaction sand column is used (see reference below) to facilitate drainage. First, the water table is lowered so that the level is just above the ground surface. A brass model of a multi-storey building (weighing 5 kg) is placed on the ground surface. Notice the amount of building settlement as it is placed on the surface of the loose sand. A gentle tap on the side of the apparatus from a rubber mallet, causes the building to topple. The sand is subsequently compacted by applying several mallet blows to the side of the apparatus. The water level is again lowered, and the build...