A method for estimating the mid-span deflection of cable-stayed bridges with temperature variation

Abstract

The invention provides a method for estimating the mid-span deflection of a cable-stayed bridge with temperature variation, belonging to the technical field of bridge structure health monitoring. Themethod simplifies the temperature variation of the cable-stayed bridge by simplifying the average temperature TG of the top and bottom slabs of the main beam, based on the temperature difference between the top and bottom of the main girder TGD, the cable temperature TC, the average temperature of the bridge tower to the sun / back sun side TP, and the temperature difference of the bridge tower to the sun / back sun side TPD, the total deflection DT is estimated by using the linear superposition model of the average temperature of the main girder, the cable temperature and the average temperatureof the bridge tower. The information of triplet (TG, TC, DT) is represented by bubble diagram, that is, the transverse and ordinate coordinates of each data point in the diagram are determined by TG and TC, and the size of data point is determined by DT. The method is convenient and suitable for site calculation, and can estimate the temperature effect only by the overall size arrangement of the bridge in the conceptual design stage, so it is convenient for scheme comparison and selection.

Description

technical field [0001] The invention relates to the technical field of bridge structure health monitoring, in particular to a method for estimating mid-span deflection of a cable-stayed bridge as it changes with temperature. Background technique [0002] Bridge mid-span deflection is a key index in bridge design and monitoring. Under the actual measurement conditions on site, this index will change considerably with the operating environment—especially the change of temperature—thus covering up the index changes caused by structural damage or degradation. If the temperature-related changes in deflection can be separated from the measured changes in total deflection, then abnormal changes in deflection caused by structural damage or degradation can be highlighted. Therefore, it is necessary to study the relationship between temperature change and deflection. [0003] At present, there are roughly two types of methods for estimating mid-span deflection changes based on tempe...

AI Technical Summary

Problems solved by technology

The shortcomings of this type of method are: 1. Lack of mechanical background, the resulting model does not reflect the causal relationship, and it is easy to miss key independent variables when modeling

2. In order to improve the applicability of the model, it is necessary to accumulate data for a long time to include various possible temperature distribution states, the cost of modeling is high and the model is difficult to promote

3. The model is completely dependent on the quality of the test data, and cannot check and verify the test results

The disadvantage of this type of method is that finite element modeling is difficult, and the analysis results are not intuitive; and different finite element models need to be established for different bridges, and it is difficult to obtain universal conclusions

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