Bridge displacement calculating apparatus, bridge displacement measuring apparatus, bridge displacement calculating method, bridge displacement measuring method, and non-transitory computer-readable recording medium

A bridge displacement calculating apparatus for calculating a displacement of a bridge induced when a vehicle passes, based on acceleration data at a predetermined location of the bridge, comprising:

• a DC component removing part for removing DC components of the acceleration data and outputting DC-removed acceleration data;
• a high-pass filter part for reducing low frequency components of input data thereto by using, as a cutoff frequency, a reciprocal of a time in which the vehicle has passed between frame bodies of the bridge;
• a first integration part for integrating input data thereto, and outputting the integrated input data;
• and
• a second integration part for integrating input data thereto and outputting displacement data, wherein
• the high-pass filter part receives the DC-removed acceleration data, the first integration part receives an output of the high-pass filter part, and the second integration part receives an output of the first integration part, or
• the first integration part receives the DC-removed acceleration data, the high-pass filter part receives the output of the first integration part, and the second integration part receives the output of the high-pass filter part.