Study on Seismic Response of Escalator in Consideration of Interaction with Building During Large Earthquakes

In Great East Japan Earthquake in 2011, fall accidents of escalator body occurred. In the fall accidents, the escalators connected the third floor and the second floor. These occurred in commercial facilities of steel frame buildings. In general, escalators are mounted within the building structure without being fixe to the beam of the building. The cause of the fall accidents was that the escalators came off the beams of the buildings as a result of the great earthquake more than expected. After the escalator accidents, the quake resistance standard was revised in Japan. According to this standard, the layer displacement of buildings to be expected during an earthquake is more than before. However, it is considered that a non-fixed part of an escalator collides with a beam of a building by an earthquake. In addition, the collision may give compression and residual displacement to the escalator. Therefore, the purpose of this study is to grasp dynamic behavior of an escalator at an earthquake which considers impact with the beam. In this paper, behavior of an escalator during earthquakes is compared by difference of restoring force characteristics of escalators and confirm the validity of the bi-linear model. In addition, as a preliminary analysis for the vibration experiments, dynamic behavior of escalators during large earthquake is investigated by a seismic response analysis model which considers interaction with the building.