LIQUEFACTION SIMULATION AND RELATED BEHAVIOR OF UNDERGROUND STRUCTURE ON OSAKA GULF COAST

Abstract

The Kansai area has a high possibility of a huge plate-boundary-type earthquake within 30 years.
If an earthquake occurs, the Osaka Gulf coast will be struck by severe liquefaction disasters. Therefore, we
tried to apply LIQCA, which is often used for liquefaction analysis, to a site on the Osaka Gulf coast. The input
earthquake motion is the seismic standard spectrum I, which is commonly used in Japan. The calculation time
continued until the excess pore water pressure dissipated. The site has an underground structure, so we
investigated not only the liquefaction phenomenon of the ground itself but also the behavior of the underground
structure. The results of this analysis indicate that these soil layers of the target area become liquefied. After
the excess pore water pressure dissipates, the ground surface settles in the vertical direction and moves in the
horizontal direction. In addition, in the vicinity of the underground structure center, it rises in the vertical
direction and moves in the horizontal direction.