EXPERIMENT AND SIMULATION OF Q-? RESONANCE USING FOUR-LAYER BENDING-SHEAR TYPE SPECIMEN

Torsional vibration of buildings subjected to earthquake motion has been studied for many years, but the torsional vibration of high-rise buildings has not yet been clarified. Many previous studies have focused on eccentricity, the mismatch between the center of gravity and the rigid center, as the cause of torsional vibration. However, in buildings with no eccentricity, torsional vibrations could be observed. The authors' research group focused on the “Q-? effect,” a phenomenon in which torsional torque is generated due to geometric nonlinearity and “Q-? resonance,” a phenomenon in which resonance occurs when the period of torsional torque generation coincides with the natural period of the torsional mode. In order to analyze the characteristics of Q-? resonance, a small-scale specimen was designed and fabricated from an 81-story high-rise building with biaxially symmetrical plans, which was reduced to four stories. As a result, the torsional response of the experimental and simulation results generally agreed, confirming that the torsional response increases when the Q-? resonance condition is satisfied. In addition, a comparison of the torsional response with a specimen with a smaller tower ratio and less bending deformation was conducted, and it was confirmed that the peak of the torsional response was steeper in the present study case.