Method for identifying bridge deflection based on long gauge length strain improved bending moment area method

Abstract

The invention discloses a method for identifying bridge deflection based on a long gauge length strain improved bending moment area method. The method comprises the following steps of: S1, determininga bridge length L and a bridge cross section neutral axis height h; S2, continuously arranging m long-gauge-length strain sensors on the bridge in the length direction, and testing long-gauge-lengthstrain measured by each long-gauge-length strain sensor under the action of any load; S3, obtaining a function relationship between deflection and strain by adopting an improved bending moment area method; and S4, calculating the deflection of a point x at the moment t on the bridge according to the function relationship between the deflection and the strain. Based on an improved bending moment area method, the function relationship between the deflection and the strain can be deduced. Deflection distribution of any point on the structure along with time change and deflection distribution of the structure at any moment can be obtained through a formula in combination with the measured strain. The method is not affected by external loads, is suitable for static loads and dynamic loads, andis high in measurement precision, good in stability and convenient to use.

Description

technical field [0001] The invention belongs to the technical field of engineering monitoring, and in particular relates to a bridge deflection identification method based on an improved bending moment area method based on long gauge strain. Background technique [0002] With the rapid development of society and the continuous progress of science and technology, my country has made great progress in bridge construction. There are more than 600,000 bridges in the country. Due to the influence of uncertain factors, improper maintenance measures after completion, natural aging of materials, overweight vehicles and accidental loads, nearly 1 / 4 of the bridges have hidden dangers such as defects, damages and functional failures of varying degrees. The safety performance and normal function of the bridge are reduced, leading to catastrophic accidents. [0003] The continuous occurrence of bridge safety accidents makes the structural health monitoring of bridges an essential work. ...

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