Abstract
Displacement has been regarded as the key indicator for health monitoring because it is closely related to running safety of trains and other structural performances of bridges. However, direct measurement of displacement is often difficult and costly because it generally requires fixed reference points. On the other hand, inertia measurements is expected to be applied for practical heath monitoring, because it has capability of wide variety of installation environments. From this point of view, we have developed evaluating methods of displacement based on the acceleration records. Developed method intended to earthquake response which does not contain high frequency components or random response, such as wind load and microtremor. In this paper we extend the method for train load which is necessary to consider not only the characteristics of the specific structure but the characteristics of the periodic external force. Proposes a theoretical basis on how to take into account periodic external force of the load train to estimate the maximum displacement from the acceleration response and verify the effectiveness of the method from the simulation and field test results at actual railway bridges.
