aside some land as a testing site for nine companies to come up with affordable ways to prevent liqefaction. one has come up with a way to create logs embedded into the ground vertically. this is how they work. liquefaction generally occurs in sandy soil that's become waterlogged. when it's shaken, the grains separate. pounding the logs into the ground increases the pressure on the surrounding soil. embedding many logs into the ground makes that area firmer. tests indicate the logs make the soil hard enough to prevent liquefaction when shaken. even in waterlogged soil, they resist decay. the company says costs can be kept down by using tree thinnings from forests. >> translator: right now nowhere else in the world is using logs as a way to prevent liqefaction. we're continuing to look at ways to make this more affordable. >> another major company has a different approach. this method involves the use of steel plates. the plates of solid steel are pounded into the ground on four sides of the house. when soil liquefaction occurs, mud comes out causing the houses to tilt. the house surrounded