Dynamic And Static Parameters And Lateral Reinforcement Analysis Of Railway Simply Supported T-Beam Bridge Considering Diaphragm Damage

Most of the existing railway bridges in early China were simply supported T-girder bridges with multi-sheet prefabricated concrete.The transverse rigidity of the bridge itself was weak,and the reasons for the rapid increase of train transport capacity,the increase of axle load and the increase of speed were not taken into account in the early design of bridges.These factors have caused the existing bridges under the action of train loads,such as excessive lateral vibration and other problems,which bury hidden safety hazards for operation.And the damage of bridge diaphragm is the main cause of the transverse amplitude exceeding the limit.Therefore,it is particularly important to analyze the damage of bridge diaphragm and carry out the transverse reinforcement analysis.Based on the special line inspection project of Huangling Railway and on the basis of onsite inspection,this paper will focus on the study and analysis of the changing law of the influence of diaphragm damage on the bridge before and after,and provide a reasonable and reliable scheme for the maintenance and reinforcement of the bridge structure through the conclusion of static and dynamic analysis,and analyze its reinforcement effect.The main contents of the study are as follows:(1)The vertical static and live loads of trains are loaded in the form of curved eccentric load coefficient.Firstly,the law of vertical deflection change of single diaphragm under different damage degree is studied and analyzed,and the influence of single diaphragm damage on bridge deflection is analyzed.Then,the law of vertical deflection change under multidiaphragm damage state is studied and analyzed.The transverse combined forces are used to load the bridge.The transverse displacement of the bridge under single diaphragm damage and multi-diaphragm damage is studied and analyzed respectively.(2)By means of ANSYS finite element software,modal analysis is carried out to analyze the variation of natural frequencies of bridges before and after damage of single diaphragm and multi-diaphragm.By means of UM software,the dynamic simulation analysis of vehicle-bridge coupling is carried out,and the dynamic response indexes such as transverse amplitude,transverse acceleration before and after damage of single and multiple diaphragms are obtained by two trains passing through the bridge at different speeds.Finally,by analyzing whether the dynamic response index of the bridge after the damage of diaphragm exceeds the norm limit,the reference limit is provided for the future maintenance of the bridge diaphragm.(3)Based on the static and dynamic analysis of the diaphragm before and after damage in the first two chapters,the transverse reinforcement design scheme is proposed according to the conclusion that the closer the diaphragm is,the greater the influence on bridge performance.Through static analysis and dynamic analysis,the changes of parameters such as transverse and vertical displacement before and after reinforcement are studied,and the reinforcement effect is evaluated.