Evaluation of vibration properties of high-rise steel buildings using data of vibration tests and earthquake observations

摘要

This paper describes the vibration properties of high-rise steel buildings using data obtained from vibration tests and earthquake observations. In the first part, vibration properties on the micro-amplitude level are examined by performing statistical analyses for vibration test data of 31 steel-structure buildings. In the translational mode, the longer the natural period becomes, the smaller the damping factor becomes, and the nth mode damping factor can be obtained by multiplying by about 1.2 for every additional mode. In the second part, vibration properties on the large-amplitude level are investigated by applying a system identification technique to earthquake records observed in a 31-storey building with an irregular-shaped plan. The natural periods estimated from the earthquake records are longer than those obtained by ambient vibration measurements. It is also shown that the damping factors in torsionally coupled modes are larger than those in translational modes.