A method for evaluating the service life of expansion joints in cable-supported bridges

Abstract

The invention relates to the technical field of bridge expansion joints, in particular to a method for evaluating the service life of an expansion joint of a cable-supported bridge, which includes obtaining an average time length for calculating the cumulative displacement of the expansion joint through a Fourier transform method, and calculating the estimated value A of the remaining service life of the expansion joint. ; Establish a correlation model between the average longitudinal displacement D of the expansion joint and the effective temperature T of the main girder within the average duration, and determine whether the average longitudinal displacement D of the expansion joint caused by the change of the effective temperature T of the main girder exceeds the design value, and The number of records exceeded is N 1 ; Take the average time as the test section, establish the change curves of the average longitudinal displacement D of the expansion joint and the effective temperature T of the main beam respectively, and record the number of intersection points of the two curves as N 2 ; Revise the estimated value A of the remaining service life of the expansion joint. The technical solution of the present invention effectively solves the influence of signal noise on the calculation of cumulative displacement, and comprehensively considers the correlation between displacement and temperature, thereby making the calculation of the service life of the expansion joint more accurate.

Description

technical field [0001] The invention relates to the technical field of bridge expansion joints, in particular to a method for evaluating the service life of cable-supported bridge expansion joints. Background technique [0002] Expansion joints are an important part of a bridge. It connects different bridge sections into a bridge as a whole, and helps to avoid excessive effects of external loads such as temperature and wind on the overall structure of the bridge, thereby effectively protecting the safety of the bridge structure. Bridge expansion joints accommodate the deformation of the bridge deck due to factors such as concrete creep and shrinkage, ambient temperature fluctuations, and traffic loads. [0003] However, expansion joints are also the accessories that bear the largest dynamic load in the bridge structure. It must bear various complex dynamic loads and impacts of different magnitudes; Physical and chemical erosion, so the expansion joint is the most vulnerable...

AI Technical Summary

Problems solved by technology

According to the statistics of many places, although the cost of expansion joints is less than 1% of the bridge construction cost, 16% of the defects in the operation process occur in expansion joints, and the related maintenance costs of expansion joints exceed 20% of the total maintenance costs. Does not include indirect losses caused by traffic interruption, severe vehicle vibration, etc.

[0005] At present, a large amount of accumulative displacement data of beam ends of expansion joints has been obtained in years of analysis and research on expansion joints of bridges. The above data are extremely important for judging the operating status of expansion joints. However, the monitoring data of the current bridge health monitoring system will be affected by various The impact of various external noises, and the consideration of factors is relatively simple, which makes the calculation of the remaining service life of the expansion joint a large error

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