Abstract
A full-scale five-story steel frame building was tested dynamically by means of a servohydraulictype vibrator to evalnate experimentally the soil-structure interaction effect. The test building consists of 6 pieces of isolated concrete footings, a five-story steel frame and concrete slabs. It is 15m long in E-W direction, 3.75m wide in N-S direction, and 17.4m high as shown in Fig. 1. A servohydraulic-type vibrator instead of a centrifugal-type vibrator was used to force the building and footings to vibrate. First of all, the building was forced to vibrate by means of the vibrator located on the roof or the first floor to examine the effect of excitation at different levels on the dynamic characteristics of the building. Excitation at the first floor makes not only the fundamental frequency increase, but also the damping ratio decrease compared with them to excitation at the roof. It is noted that the first floor response to excitation at the first floor level decreases in the neighborhood of the frequency corresponding to the resonant frequency of the building with the fixed base.
