Early warning threshold setting method based on moving interval relevance trend

Abstract

The invention discloses an early warning threshold setting method based on a moving interval relevance trend. The stable and sensitive relevance relationship between the monitoring data is utilized; arelevance trend line and a structural response normal value envelope line are obtained by adopting relevance movement interval probability statistical characteristics, and then a red early warning limit value is obtained according to a certain guarantee rate on the basis of the normal value envelope line based on a reliability theory, so that a 'two-line three-area ' relevance early warning mechanism is established, and relevance early warning of the system is realized. Compared with a fixed and single time-history early-warning threshold of structural response data, relevance trend early-warning belongs to a comprehensive early-warning system, and massive monitoring data of the bridge health monitoring system can be fully utilized and the internal change rule of the monitoring data can be mastered. The relevance trend early warning threshold value changes along with the change of relevance characteristics, and the dynamic threshold value has higher precision and sensitivity, so thatthe system can give an early warning more scientifically in real time. The method has been realized in a programmed manner, is simple and quick to operate, and has wide engineering application value.

Description

technical field [0001] The invention relates to a method for setting an early warning threshold based on the correlation trend of moving intervals, and belongs to the technical field of bridge structure data analysis and research. Background technique [0002] At present, the research on the bridge early warning system is of great significance to the bridge safety assessment, and at the same time, it is also the core content of the operation monitoring early warning evaluation system. For the operation monitoring system, whether it can carry out accurate and timely early warning assessment will be directly related to whether some special events can minimize the adverse effects caused by the event and ensure structural safety. [0003] In recent years, with the development of the operation monitoring system and the continuous improvement of related technologies, various early warning systems of the bridge health monitoring system have also been widely used in engineering prac...

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Problems solved by technology

[0004] At present, the common early warning threshold setting methods of bridge health monitoring system are: (1) normative limit value, which is based on the norm and obtained on the basis of a large number of experiments, and it is general in the application of conventional bridges. Due to the particularity of deformation and stress characteristics of permanent bridges and long-span bridges, the standard limit values ​​should not be adopted. At the same time, the standard limit values ​​are often conservative, and it is difficult for the measured data to reach the limit value for effective alarm, and the structural response reaches the standard limit. When the value is high, the structure is often damaged, and it is impossible to timely warn and deal with it

(2) Structural finite element analysis of the most unfavorable working condition combination value, this type of early warning threshold setting method is based on bridge structure finite element analysis, considering all working conditions, extracting the structural response value of the measuring point position under the most unfavorable working condition, this type of early warning threshold It is widely used and can be used as the early warning threshold of the system. However, the scientificity of the early warning threshold based on the structural finite element analysis depends on the accuracy of the model establishment. At the same time, the most unfavorable load conditions are difficult to appear in the normal operation of the bridge. , there is a certain degree of conservatism in the set early warning threshold

(3) Statistical values ​​of monitoring data. This type of early warning threshold setting method is based on the probability statistics method. On the premise that the monitoring system collects sufficient data, the quantile value extracted according to a certain guarantee rate, this type of early warning threshold setting method has certain advantages. Statistical significance, but the early warning threshold setting is relatively simple

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