This invention relates to the field of dynamic disturbance measurement technology, specifically to a method and apparatus for measuring vertical dynamic disturbance of high-speed railway bridges. The method involves taking a subsequence at each sampling moment in the
vertical displacement time series at a key section of the bridge, using a sliding window centered on that moment, and identifying local extreme points. The extreme
point density and amplitude dispersion are determined based on these local extreme points. The extreme
point density and amplitude dispersion are processed to obtain normalized
distortion. An adaptive threshold is constructed based on the normalized
distortion. The sequence or the unprocessed residual components from the previous
decomposition are used as the
signal to be decomposed, and iterative sieving is performed to extract intrinsic mode functions (EMFs). Each sieving iteration calculates the local deviation. If the local deviation is less than the adaptive threshold and meets preset constraints, the iteration terminates and the EMF is output. The obtained EMFs are used to reconstruct the
signal, resulting in the vertical dynamic disturbance waveform, thereby improving the accuracy of vertical dynamic disturbance measurement.