Impact and vibration method for measuring natural frequency of bridge lower structure

Abstract

The invention relates to an impulse vibrating method for testing the bridge substructure natural frequency of vibration which uses avoirdupois weight to stroke the pier and tests the vibrating response of the pier to analyze and compute the natural frequency of vibration. It uses avoirdupois weight to stroke the pier top part and tests the speed and hastens response of the bridge. It usually dose multi-stroke and uses the recording wave mode superposition to dispel the noise to obtain the accurate response wave mode. It reads the response wave mode to do Fourier analysis to ascertain Fourier frequency spectrum and combines with the peak spectrum to ascertain the natural frequency of vibration of bridge.

Description

technical field [0001] The invention relates to a method for measuring the natural vibration frequency of a bridge substructure. Background technique [0002] The natural frequency is an inherent property of the bridge substructure and is determined by the stiffness and mass of the pier system. When the bridge pier is damaged, it is generally believed that the disease only changes the stiffness of the system without changing the quality of the system, so the change of the natural frequency can reflect the change of the stiffness of the bridge pier, that is, the disease. When the bridge pier vibrates laterally, the restraining effect of the beam and the track is very small and can be ignored, so the lateral natural frequency is very sensitive to the disease. Based on the above reasons, using the natural frequency index to judge the soundness of bridge piers has always been a research hotspot at home and abroad. The basic idea of ​​this method is: given the base natural freq...

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Problems solved by technology

[0003] The "Journal of Beijing Jiaotong University" published in February 2005, Volume 29, Issue 1 "Shock Vibration Test Method for Testing the Natural Frequency of Existing Bridge Piers and Abutments", described the basic principles and implementation steps of measuring the natural frequency of bridge piers by shock vibration. A brief introduction and application examples are given, but this document does not give specific measures for time-domain signal interception and superposition to eliminate signal noise, nor does it give a specific method for realizing the phase spectrum of the impulse response signal.

Simply based on the content disclosed in this document, technicians in this industry cannot use this method to measure the natural frequency of the bridge pier

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