Causes And Prevention Measures Research Of Orthotropic Steel Deck Crack On Long Span Bridges

Orthotropic steel deck has to face severe fatigue problems due to its numerous crisscrossed slabs, as well as the influence line is short, the phenomenon of stress concentration is obvious, which result in complex mechanical state and significant stress concentration. The orthotropic steel deck fatigue crack often appears together with the disease of bridge deck pavement, two diseases influence each other, reciprocal causation. At present, the fatigue design of orthotropic steel bridge deck generally take the structural details of bridge decks itself into account, the idea of integral design of bridge deck and pavement layer combination relatively few. In this paper, taking the Jiangyin Yangtze River Highway Bridge as an example, analysis of the fatigue life of the typical position of this bridge. And as the idea of integral design of bridge deck and pavement layer combination, put forward treatment measures of large span bridge of orthotropic steel bridge deck and deck pavement fatigue cracking. The calculation results show that using ECC(Engineered Cementitious Composite) as bridge deck pavement material can improve the fatigue life of the bridge deck. The research content is divided into the following aspects:(1) Reviews the development history of the orthotropic steel deck, summarized the main form and position of fatigue crack about the orthotropic steel deck, while finishing the current form of typical pavement about the orthotropic steel bridge deck;(2) Researched the disease of bridge deck pavement and weld fatigue crack appeared in the Jiangyin Yangtze River Highway bridge since it opening operation. According to the results of classification, analysis of the basic characteristics of long span bridge of orthotropic steel bridge deck disease at the same time;(3) Based on the result of detection, and the finite element analysis, the stress distribution of the orthotropic steel deck under vehicle loads is been described, lay the foundation for calculating the fatigue life of fatigue details;(4) Reviews the analysis of the basic concept, calculation methods and ideas about structure fatigue. At the same time use the linear fatigue damage accumulation theory, calculate the fatigue life of orthotropic steel deck fatigue details. By contrast with the actual situation, the calculation is proved right.(5) Using the idea of integral design of bridge deck and pavement layer combination, put forward a treatment measure of large span bridge orthotropic steel deck fatigue cracking and the disease of bridge deck pavement——ECC steel combination bridge deck. Through the analysis of fatigue life about the pavement and the deck, verify the effectiveness of the treatment.