抄録
About 27,000 wooden houses were damaged due to liquefaction during the 2011 Great East Japan Earthquake. There are four possible patterns to reconstruct damaged houses and/or areas. The author and his colleagues developed a new method by enclosing individual house by sheet piles. Effectiveness of the method was demonstrated by shaking table tests. On the contrary, if all or many settled and tilted houses are temporary repaired by uplifting, the ground in the whole area must be treated by special measures to prevent re-liquefaction. The MLIT established a new project, the “Urban liquefaction countermeasure project”. In this project, a wide existing residential area is treated by an appropriate countermeasure and its costs are shared by government and inhabitants. One of the available countermeasures is lowering the ground water table by drain pipes. The applicability of this method has been studied by in-situ tests, centrifuge tests and analyses. The construction of the drain pipes has started in three cities.
