Method for monitoring dynamic deflection of high-speed rail bridge based on single-frequency GNSS positioning technology

Abstract

The invention provides a method for monitoring the dynamic deflection of a high-speed rail bridge based on a single-frequency GNSS positioning technology. The method includes following steps: S1, a receiver obtains GNSS single-frequency carrier phase observation values of a base station and a bridge monitoring site in real time; S2, a to-be-monitored satellite is selected by employing a factor dual restraint method of E-ADOP and GDOP; S3, a convection layer real-time model is established based on a spherical cap harmonic analysis, and a convection layer delay is resolved; S4, a multi-path real-time model is established, a multi-path error correction value is resolved, and a satellite-earth distance value is updated according to the error correction value; S5, a GNSS single-frequency carrier phase double-difference observation quantity is calculated based on the convection layer delay and the updated satellite-earth distance, and the ambiguity is resolved; and S6, performing back substitution of the ambiguity, calculating a three-dimensional coordinate value of the monitoring point of the bridge in real time, and obtaining a dynamic deflection value of the bridge. According to the method, the operation and the calculation are simple, the dynamic deflection of the high-speed rail bridge can be automatically monitored in real time, measuring data is continuously corrected throughmodeling, and the accuracy of dynamic monitoring of the bridge is improved.

Description

technical field [0001] The invention relates to a method for real-time monitoring of dynamic deflection of a high-speed rail bridge, belonging to the technical field of bridge health monitoring. Background technique [0002] With the development of the economy, railway bridges are becoming more and more popular. In the process of operation, railway bridges will inevitably experience aging and damage, and the bearing capacity and safety of bridges will decrease. Therefore, since the 1990s, bridges have been developed at home and abroad. Research on health monitoring. Among railway bridges, high-speed railways operate at a high speed within 250 to 350 kilometers per hour, and most of the high-speed railway bridges are built in the wild, with spans of more than 100 meters. Therefore, the dynamic performance of high-speed railway bridge structures requires higher stiffness. It is required to have strong bending and torsional rigidity to prevent large deflection deformation and ...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the problem that the current high-speed rail bridge health monitoring technology is not mature enough and the cost is high, the present invention proposes a method for monitoring the dynamic deflection of the high-speed rail bridge based on single-frequency GNSS positioning technology. Receivers are set at the monitoring points of the high-speed rail bridge and combined with satellites to obtain real-time The GNSS single-frequency carrier phase observation value of the base station and the bridge monitoring point eliminates part of the error of the observation value through the tropospheric delay and multipath error correction number, and finally uses the corrected observation value to solve the three-dimensional coordinates of the high-speed rail bridge monitoring point in real time

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