微動測定に基づく地震被災鉄骨建物の層損傷評価

抄録

A method to evaluate interstory stiffness and damping based on ambient vibration measurements is presented. The method was applied to two steel buildings, both of which were damaged during the strong earthquake motion of the 1995 Hyogoken-Nanbu earthquake. Through comparison before and after repairs, the following results were obtained. (1) Damages to beam-to-column connections in a moment frame structure caused reduction of interstory stiffness by 20 to 30 percent. (2) Fracture of bracing members in a braced frame structure caused reduction of interstory stiffness by about 50 percent. The obtained results can be utilized as a standard reference for developments of damage detection methodology.