Evaluation method of remaining service life after fatigue cracking of in-service orthotropic steel bridge decks

Abstract

The invention provides a method for evaluating the remaining service life of an orthotropic steel deck slab on active service after fatigue cracking. The method specifically comprises the steps of (1) measuring the actual length a0 of each crack by adopting a non-destructive testing technology, (2) monitoring actual strain data of the two sides of each crack by adopting strain sensors, (3) obtaining stress process data of each crack, (4) calculating the daily mean equivalent stress amplitude delta sigma eq and the daily mean equivalent stress cycle index Neq according to a rain flow method and a Miner accumulation criterion, (5) determining the tolerance limit length ac of each crack by combining actual situations on the basis of rigidity and strength criterions, (6) calculating the propagation life Nc and Dc of each crack on the basis of a Paris formula, and (7) taking the minimum value of the Dc of all the cracks as the remaining fatigue life Dc, min of the steel bridge deck slab. The method for evaluating the remaining service life of the orthotropic steel deck slab on active service after the fatigue cracking is reliable in theory, clear in logic, and simple in detection means and method.

Description

technical field [0001] The invention relates to the technical field of bridge health monitoring, in particular to a method for evaluating the remaining service life of an in-service orthotropic steel bridge deck after fatigue cracking. Background technique [0002] Orthotropic steel bridge decks are widely used in large and medium-span bridge structures due to their light weight, high overall efficiency, strong spanning capacity, and good seismic performance. However, due to the complex structural stress, difficult control of welding defects, and direct bearing of vehicle dynamics, the orthotropic steel bridge deck is also the most prone to fatigue damage in steel bridge structures. Since the first discovery of fatigue cracks in the structural details of steel bridge decks in the British Severn Bridge in 1971, there have been reports of fatigue cracks in steel bridge decks in Germany, France, Japan, the United States, the Netherlands and other countries. my country's Humen B...

AI Technical Summary

Problems solved by technology

Because of this, when the fatigue cracking problem occurs in the orthotropic steel bridge deck in actual engineering, relevant personnel cannot accurately predict and evaluate the remaining crack growth life, which leads to blind opening of crack holes, crack filling and repairing, Measures such as crack reinforcement and reinforcement will not only cause unnecessary economic waste, but may also cause secondary damage to the structure

However, if some cracks in key positions or oversized cracks are not dealt with, it may also bring safety hazards or obstacles to the bridge structure.

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