ANALYSIS OF FACTORS IN DAMAGE OF COLLAPSED HOUSES CAUSED BY THE 2003 MIYAGIKEN-OKI EARTHQUAKE BASED ON MICROTREMOR MEASUREMENT AND MANPOWERED FORCED VIBRATION TEST(Structures)

Abstract

The two adjacent houses built by different constructions were only judged as fully-collapsed ones hit by the 2003 Miyagiken-oki Earthquake. The factors in damage of these houses were investigated through micro-tremor and forced vibration measurements. Because those houses were located on a hilly area having shallow soft deposit, the site ground motion might be amplified due to soil and topography interaction effect. The predominant frequencies of damaged houses were so close to those of earhtquake ground motion that the frames should be eggectively shaken. The twisting behavior of the houses enhanced by ground failures and structural destructions would accelerate the enlargement of damage.