NUMERICAL STUDY OF STRUCTURE-SOIL-GROUP PILEFOUNDATIONS USING AN EFFECTIVE STRESS BASED LIQUEFACTIONANALYSIS METHOD

摘要

Seismic behavior of pile foundations is widely discussed by many researchers in order to do research of saferand more economic designs for the infrastructure during earthquakes. In usual, civil structures areconstructed on a foundation with group piles installed rather than a single pile, moreover, the interactionamong soils and piles depends on the liquefaction of surrounding ground of the infrastructure. The authorscarried out a of liquefaction analysis using an effective stress based liquefaction analysis method on a realstructure-pile foundation-ground, in which a five story building in Kobe area was shocked to damage in 1995Hyogoken-Nambu Earthquake. In the present numerical simulations, we adopted a numerical code LIQCA3Dwhich was developed by some of the authors. From the numerical simulations, it was found that theacceleration responses, velocity responses and displacement responses of the ground agree well with theobservations, and the distance of the piles installed in the footing influences the built-up of the excess porewater pressure and the damage on both pile heads and low segments of the pile at the boundary takes placebefore the complete of liquefaction during these major earthquakes.