We can and do build the building and other heavy structures on wet sandy soil, since the weight of the grain and the friction between them make the soil behave as solid most of the times. But during an earthquake, soil particles repeatedly moved back and forth so much that the water can't flow away. read more
The building codes in many developed countries require engineers to consider the effects of soil liquefaction in the design of new buildings and infrastructure such as bridges, embankment dams and retaining structures. read more