The Fatigue Damage And Life Estimation Of Maurer Expansion Joints

With the increase of traffic volume and overweight vehicles in recent years, Maurer，as alarge displacement expansion joints，has been widely used. The damage of expansion jointsled by repeating traffic load usually leads drivers feeling uncomfortable and bridge structuredamaging. However, fatigue is one of the main reasons of Maurer expansion joints’damage. Itis very important to analyze the fatigue failure of Maurer expansion joints and providemethods about high way maintenance to improving driving condition, assuring the drivingcomfortably and the durability of bridge. On the basic of theories and experiment, takingMaurer expansion joints of the third bridge of Xiangtan as an example, fatigue life wasestimated and factors affecting the fatigue life of Maurer expansion joints were proposed inthis paper.On the basic of design specifications of bridge expansion device, fatigue theory andknowledge of structural dynamics, researches were carried out to study the Maurer expansionjoints’ dynamic property. Dynamic stress of Maurer expansion joints under a given axle loadand the speed of the vehicle situation was studied on the basic of dynamic stress testexperiment. The stress spectrum are obtained. finite element model of Maurer expansionjoints was established to analyze its stress histogram under different working loads situationand the change rules of stress was got. The factors that affect stress of expansion joints wereanalyzed in this paper, mainly including the influence that the changes of sliding bearing andelastic bearing of modulus of elasticity and stiffness to the expansion joints. The influencethat the changes of bearings damping to the stress of middle beam was researched.Considering various factors about expansion joints, fatigue life of Maurer expansion jointswas analyzed on the basis of experimental and theoretical data and some suggestions aregiven. According to the study results, some suggestions about maintenance and design ofMaurer expansion joints are given. It has practical significance for improving the life ofMaurer expansion joints.