Abstract
A method is presented to measure the magnitude of earthquakes from the slip displacement of the friction-controlled SDOF system. A statistical relation among JMA magnitude, slip displacement, focal distance, and the critical acceleration of the system is obtained with 52 sets of strong motion accelerograms in Japan. This relation is then used as a measurement equation of the magnitude of earthquakes from slip displacement. The estimated magnitudes at various sites are found to be consistent within each earthquake with an averaged standard deviation of 0.10. The proposed method can be used to measure the magnitude of earthqrakes from various sources such as slip displacement measured in a block on an inclined plane, earth dams, slopes, and other structures.
