Abstract
The range of liquefaction caused by the 2011 Great East Japan Earthquake was very wide, from the Tohoku region to the Kanto region. Post-earthquake studies have shown that the reasons for this wide range were the long duration of shaking and continuous aftershocks. In many residential areas, roads and lifelines were damaged at the same time as wooden houses, making it difficult to live in these areas. Therefore, measures such as lowering the groundwater level were taken to prevent an entire city area from liquefying due to future earthquakes. In the hills, many areas where valleys had been filled with soil to make them residential areas suffered severe damage, such as slides of slopes and subsidence of the fill. Since many similar filled residential areas have been constructed in Japan, their stability during future earthquakes is currently being checked.
