Roadbed dynamic displacement determination method based on dynamic stress and vibration displacement time history signals

Abstract

The invention discloses a roadbed dynamic displacement determination method based on dynamic stress and vibration displacement time history signals. The roadbed dynamic displacement determination method comprises the following steps that S1, roadbed dynamic stress time history signals and roadbed vibration displacement time history signals caused by train operation are collected; s2, obtaining a roadbed dynamic stress normalization time history curve and a roadbed vibration displacement normalization time history curve; s3, acquiring a lower envelope curve and an upper envelope curve; s4, determining a roadbed dynamic displacement time history curve; and S5, determining a railway roadbed dynamic displacement value. According to the method, on the basis of an actually measured roadbed dynamic stress time-history curve and a roadbed vibration displacement time-history curve, a roadbed dynamic displacement time-history curve is obtained through correction by using a signal processing technology, a sensor used for testing is directly placed at a measuring point part, and additional fixed points and rigid supports do not need to be selected; the contradiction between the position of a fixed point and the size of the rigid bracket caused by the limitation of the environment in the existing test method is overcome.

Description

technical field [0001] The invention belongs to the technical field of roads and railways, and in particular relates to a method for determining dynamic displacement of roadbed based on dynamic stress and vibration displacement time-history signals. Background technique [0002] Train operation imposes moving axle loads on the line structure, and at the same time generates dynamic excitations caused by track irregularities and wheel out-of-roundness. The line structure directly bears the train load, and its service performance is related to the safety of high-speed rail operations. As a main type of off-line structure, the subgrade needs to fully consider the impact of train dynamic loads in the process of design, construction and operation and maintenance. The dynamic response test results. The subgrade is a geostructure filled with granular materials, and the dynamic test should not only reflect the response of the surface of the structure, but also pay attention to the ...

AI Technical Summary

Problems solved by technology

The existing methods mainly use sensors such as LVDT and eddy current, and clamp the sensor on the rigid support drawn from the fixed point. The fixed point and the measuring point are both located on the subgrade structure due to environmental restrictions, and there are the following problems: ① Use a small Large rigidity bracket, the position of the fixed point is close to the measuring point, and the background response of the fixed point will inevitably increase the test error; ②Increasing the distance between the fixed point and the measuring point to ensure the rigidity of the bracket will inevitably lead to an increase in size, which will greatly increase the test cost , may also affect the safe operation of high-speed trains, while limiting the size of the bracket may not be rigid enough, and the deformation of the bracket structure caused by the train load will also increase the test error

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