Abstract
This paper studies the damage reduction effect due to the basemat uplift of buildings which are subject to strong ground motions. First, I demonstrate a simulation analysis result of a slightly damaged building during 1995 Hyogo-Ken Nanbu earthquake, while it is located in Chuo-Ward and its surrounding buildings were heavily damaged. Drastic damage reduction was caused by the nonlinear soil-structure interaction effect due to the soil nonlinearity, neighbouring structures and the basemat uplift. Among those reasons, basemat uplift effects are studied by varing the shear wave velocity of the soil, the dimension, shape, and strengh of buildings, and the kind and intensity of input motions. In conclusions, the damage reduction would have been drastic for slender buildings whose foundation size is less than 15m, number of story is less than 15 during 1995 Hyogo-Ken Nanbu earthquake. However, the reduction extent is completely different due to the strength of building, the kind and intensity of input motions.
