Study On The Regularity Of Performance Change Of Slab Repair For Ballastless Track Plate Of High Speed Rail

The position of railway in the integrated transport system is regarded as the backbone position,and the high-speed railway plays an increasingly essential role in China’s transportation system.The”13thFive-Year Plan”has mentioned that the country should speed up the improvement of high-speed railway network and aims to expand the operating mileage over 30,000 km in 2020,which covers more than 80%of the metropolis.The safety of operating high-speed railway is the vital part of the rapid development of high-speed railway.However,the structure of ballastless track,as the unique structure of high-speed railway,has appeared immense cracks on the surface of track plate during the process of construction,which cause serious damage to the ballastless track structure of the mechanical properties and durability,and further affect the safety of high-speed railway operation.Regarding to the series questions of track plate cracks,when to maintain,how to repair and the track performance after repairing have become the current problems that countries should pay attention to.Bearing those in mind,this paper focuses on the geometry of the crack,which has impact on mechanical properties of track plate,and subsequently the durability of track plate before and after repairing cracks.The main contents and conclusions are as follows:(1)According to the existing track plate strength and durability requirements,the test will be conducted through a large number of indoor trial,resulting in the best ratio.The representative size of the crack for orthogonal test will be selected via the investigation and literature,which will focus on the influence of the geometrical size of the fracture on the strength of the track plate.Such measure will provide reference for the development of the relevant rules of crack repair in track plate.However,the results show that the crack length has a great influence on the strength of the track plate,and the influence of the length should not be neglected when developing relevant crack repair norms.(2)Select the larger and smaller size cracks in the above test crack size and arepresentative repair material-AB glue is an essential part to repair the crack via low pressure grouting method,which used to test the mechanical properties of the specimen before and after the crack repair and subsequently compared it with the test data of no crack specimen.However,the results reflect that the mechanical properties of the track plate do not meet the requirements of the design of the railway concrete when the crack size is the unfavorable combination.While the favorable combination of the crack size is better than the unfavorable combination.(3)The same method mentioned above is used to study the variation of the durability of track plate before and after crack repair.The results show that the anti-freeze-thaw performance of the track plate does not meet the requirements of designing railway concrete after repaired when the crack size is the unfavorable combination.While the anti-permeability and anti-carbonization can meet the design requirements.However,the favorable combination of crack size has the same results as the unfavorable combination.As a result,the smaller the crack size when repair,the better the durability of the track plate.