地震時における地波現象と帯水層の液状化  [in Japanese] On the ground wave, so called "Jinami", and the liquefaction of aquifer during the earthquake  [in Japanese]

This paper is represented the relation between the ground wave phenomenon and the liquefaction phenomenon of aquifer during the earthquake. The former phenomenon is always observed on the surface of the allurvial plain, especially of the areas reclaimed from swamp or lake. The latter phenomenon is generally explained as follows: As a result of increasing the pore pressure of the aquifer mainly composed of fines and with shearwave of the earthqukake. The joint parts among grains are released and the aquifer is liquefied as well. Moreover, it is important that the following mechanism on the above mentioned liquefaction should be considered. The long period hydropressure-wave synthesized in the groundwater basin, the sub-groundwater basin and the aquifers during the earthquake raises the pore-pressure of sand in the aquifers. As a result, the aquifer without confined pressure may be changed into the liquefer.