The Settlement And Dynamic Response Analysis On Rail Reinforcement Structure Of The Underrunning Railway Frame Bridge

With the constant improvement of the traffic network in China,a large number of grade crossing of highway and railway began to emerge.In order to improve the efficiency of the traffic lines,the grade crossing need to be transformed into interchange construction.In this engineering,traversing under railway framework bridge is transformation form that more be used because the construction of the the traversing of railway can not to be interrupted.The construction of the framework bridge is bound to cause disturbance of surrounding soils and make the surrounding strata displacement and deformation.And coupled with the mechanical deformation of rail reinforcement system,it needs to be further study that trains can safely through the railway construction stage.In view of this kind of situation,this paper studies the impact of frame bridge construction matter to rail reinforcement system.Construct a three dimensional model of soil-Rail reinforcement structure.Calculation and analysis the settlement of rail reinforcement structure in the frame bridge jacking construction.When each excavation step away from the 1.00 m,1.50 m,2.00 m,2.50 m,simulation of the frame bridge jacking construction process and calculated sedimentation value of rail and i-beam girder after each step excavation.Then calculated maximum subsidence value of rail reinforcement system under different excavation step distance.Get the settlement regular of lines and rail reinforcement system.Monitoring the settlement of engineering in jacking process.Conclusion the settlement regular of track structure according to monitoring data in practical engineering.Monitoring data and calculated data were compared,track settlement values monitored is close to the track settlement value calculated.The reliability of the conclusion was verified.From the monitoring data can be obtained that longitudinal beam of the sedimentation value increased and meet the specification requirements.Settlement of volatility illustrates the prefabrication of box frame and orbital uneven sex began to emerge.The train be simplified as the mass in the spring according to train's actual axle load and wheel spacing.The rail steel was simulated as beam element and establish wheel-rail dynamic action calculation model in accordance with engineering practice.Analyze the influence of wheel-rail vertical load for the structural system.Draw a line dynamic response rule by contrast beam girder vibration displacement and acceleration at different stages.Finally it was concluded that the vertical displacement of longitudinal beam increase and the acceleration decreases with the deepening of the frame bridge jacking.