Vibration Detection of High-speed Railway Bridge Using Millimeter Wave Radar Measurement System

Abstract:

To meet the real-time， high-precision and non-contact vibration detection requirements of high-speed railway bridge， this paper investigates the theory of vertical vibration model of bridge and the precise ranging algorithm of millimeter wave radar. Based on the IWR1443 millimeter wave radar chip， a millimeter wave radar measurement system is developed to realize the integration of vibration signal measurement， acquisition， decoding and processing. Then the vibration detection experiment of 32m simply supported bridges in Xuzhou section of SUIHE super large bridge on Beijing-Shanghai line is carried out with this measurement system， and the data are analyzed by time-frequency analysis method. Analysis results show that the three-dimensional spectrum array， which is extracted by the generalized S-transform and the standard time-frequency transform， reveals the bridge vibration process under the dynamic load of the high-speed train. The dynamic vertical deflection， the deflection span ratio， the main frequencies and vibration type of bridge are determined， which are consistent with the theoretical analysis， and the performance of bridge structure is better than current design limit value of high speed railway. This indicates the SUIHE bridge structure is in good health and verifies the accuracy and effectiveness of millimeter wave radar measurement system.

Key words:high-speed railway;simply-supported girder bridge;millimeter wave radar measurement system;vibration detection;dynamic deflection