Optimization of Seismic Shutdown Level for Elevators Based on Maintenance Record Data

The optimum seismic shutdown level for elevators, which will reduce the number of shutdowns occurring without seismic damage, is estimated. This estimation uses maintenance record data of elevators for obtaining seismic-shutdown-ratio curves and damage-occurrence criterion, which are then used to determine the shutdown-level margin. It was thus revealed that the newly revised shutdown level (150 cm/s2) for rope elevators corresponds to a safety factor of 1.4 and the shutdown level for hydraulic elevators can be raised to 75 cm/s2, which corresponds to the safety factor comparable to rope elevators. It is concluded that seventy percent of shutdowns can be eliminated by adopting these new shutdown levels.