Determination of Maximum Residual Displacement from Velocimeter Records: Part 2. Methods and Results of Estimating Residual Displacement

Resumo

This is the second and final part of an article on determining maximum residual ground displacement from velocimeter records. Part 1 of the article considers methods for calibrating velocimeters; Part 2, methods for assessing and reconstructing velocimeter records of irreversible deformations occurring in the epicentral zone after destructive earthquakes. An analytical residual displacement model is proposed, which can be used to simulate displacements in synthesized accelerograms. The operation of installing residual displacements into the waveforms of simulated ground motions is briefly described. According to this model, it is possible to estimate residual displacements. Examples of reconstructing residual displacements recorded by a velocimeter on a vibroplatform are given. A simple algorithm for estimating residual displacements based on interactive filtering of a long-period trend is described. The algorithm is realized in the time domain and takes into account the velocimeter’s amplitude-frequency response. The efficiency of the algorithm was tested on a synthesized accelerogram containing residual displacements. The algorithm was successfully tested on records of explosions.