Research On Synthetical Engineering Test And Evaluation Of Existing Railway Speed-Up

The speed-up of the existing railway lines is one of the main development direction of railway in China,due to the different from traditional new railway construction, and started late in our country, there is no a lot of successful experience for reference. In order to guarantee the safety and comfort of passenger when trains running after speed-up, evaluating the results of the speed-up and reconstruction project,the paper test and evaluate composite indicator of the whole structure after line and subgrade speed-up and transformation, combining with the shanghai-kunming line project.In the line, select radius2200m curve、Roadbed-bridge Transition Section and high lift road section of shanghai-kunming line as testing typical sections, combining the dynamic pile test and long-term observation method to get the wheel-rail interaction force, derailment coefficient, wheel unloading rate data, grasps the track geometry change rule, it is concluded that track evaluation conclusion:1. Through the test on dynamic effect of the track when passenger train and freight train past the2200m curve radius section at low speed, found that about80%of the train operate in a state at the over cant in the curve, transportation conditions on the destruction of the curve track are obvious, the applied force of vehicle in strands of Orbitals in stock is too big to keep the track regularity and need larger maintenance work of Lines. Various types of Train Operation Safety index are lower than those of related specified value, traffic safety is guaranteed.2. The wheel-rail interaction force of transition section between bridge abutment and Embankment, the strength of track structure and components of the overall meet the operation requirements,reinforcement section of transition section between bridge abutment and Embankment reduced the wheel-rail interaction force efficiently, which is beneficial to keep the track regularity. 3. High lift absolute bed section ballast bed parameter test results are normal, the dynamic pile test results are in safety limit range.In the roadbed, by using method of combining with dynamic pile test which use test car pass the preset station records subgrade bed dynamic load and dynamic deformation and its change rule and static test method which use the set settlement observation point, to carry on the long-term settlement deformation observation to evaluate the adaptability of the subgrade, through the evaluation analysis found that:1Transformation line subgrade bed insufficiency of bearing capacity commonly, we need to strengthen the maintenance of subgrade or increase the ballast bed.2Combined with comprehensive previous test results of speed-up line subgrade, in all load and deformation character, axle load is the important factors that influence the dynamic index of roadbed, comparatively speaking, not as well as the speed is. the influence of the train and strengthen the orbit and the maintenance of the roadbed should be mainly consided in speed-up project.3The dynamic stress and dynamic deformation value of van is greater than the bus test value and the dynamic deformation test value of reconstruction of section appears individual partial larger mainly due to the reform’s time is too short for ballast to stable.The research mentioned above shows that: through the test, research and statistical analysis, the evaluation process of comprehensive situation of existing lines speed-up shows its compliance with line safety index and driving conditions or not, the evaluation established on the basis of the test line and subgrade shows rationality and comprehensive.