This project belongs to the field of transportation science and technology.
With the rapid development of my country's railways, large-scale seamless transformation and speed up of existing railway lines have been implemented, and the speed of new passenger dedicated lines has been increased to 200km/h or above. Therefore, it is required to lay cross-regional seamless lines at one time and achieve the design speed target value, which puts forward new technical requirements for the existing key track components-bonded insulated joints. The strength of bonded insulation joints originally used in China (including Schmitt MT bonded insulation in Germany) basically meets the technical standards of 160km/h and below, and cannot meet the technical requirements of bonded insulation joints used on 250km/h lines. Due to the high running speed of the train after the speed increase, the vertical impulse and longitudinal and lateral forces on the joint when the wheel passes through the joint tend to increase significantly. Therefore, the comprehensive technical indicators such as impact resistance, shear resistance, and bending resistance of the joint need to be improved accordingly. To this end, the Scientific Research Institute of the Shanghai Railway Administration and the Public Works Department carried out research on planned projects of the Shanghai Railway Administration.
The rail glued insulating joint adopts the form of a double-sided lap joint. It is assembled with the rail on site to form an H-shaped structure by a composite insulating clamp plate, rapid curing glue, high-strength bolts, insulating end pieces and insulating sleeves. It can be suitable for on-track temperatures of minus 10 degrees Celsius to 70 degrees Celsius, on-site glue bonding of 60kg/m rail insulated joints. Its technical indicators meet the requirements of the Ministry of Railways "Technical Conditions for Bonded Insulated Rails"(TB/T2975-2000) and the Shanghai Railway Administration Enterprise Standard "On-site Bonded Insulated Joints for 60kg/m Rails"(Q/SHT29 -2009), meeting the requirements of my country's railways for one-time laying of cross-regional seamless lines, which plays an important role in ensuring fast, smooth and safe train operation.
Key innovation points: A number of technological innovations have been achieved, mainly including: by installing reinforcing ribs on the upper and lower sides of the joint steel cleats, the overall vertical and horizontal moments of inertia of the joint are enhanced, and the overall structural strength and rigidity of the joint are improved; By increasing the length of the steel cleats, the effective bonding area between the cleats and the rail is expanded; by adjusting the adhesive ratio, the pressure sensitive characteristics of the adhesive are improved, and the performance of rapid on-site bonding is improved; By improving the production process and on-site assembly and construction process of the composite insulating plywood factory, the overall shear strength and electrical insulation properties of the joint have been improved. In addition, the initial curing time of the joint at room temperature is less than 45 minutes, and the specified shear strength can be reached when construction is completed.
Technical and economic indicators: overall shear strength ≥3250KN; electrical insulation: resistance value in dry state>10 M Ω, resistance value in wet state>1 kΩ; initial curing time of adhesive <45 minutes (room temperature).
In 2008, it passed the appraisal of scientific and technological achievements by the Shanghai Railway Bureau, reaching the domestic leading level. In 2009, it obtained 1 national utility model patent. Published 3 papers in Shanghai Railway Science and Technology magazine. In 2013, this achievement was awarded the CRCC Railway Product Certification Certificate issued by China Railway Product Certification Center.
Application promotion and benefits: Since September 2008, this glued insulated joint has been well promoted and applied in various works sections of the Shanghai Railway Bureau, and has withstood the test of low temperatures in winter, rain, snow and freezing and high temperatures in summer. Practice has shown that its electrical insulation properties and shear resistance have met the design requirements, the appearance of each component is good, and the joint performance is stable, which can fully meet the on-site use requirements of the high-speed section of the passenger dedicated line. At present, this achievement has been promoted and used in batches on existing speed-up lines, passenger dedicated lines and high-speed railways of Shanghai and Nanchang Railway Bureaus. It provides strong technical support for promoting the rapid development of seamless railway lines in my country and greatly improves the operation of railway passenger trains. Stability, safety and comfort have achieved significant social and economic benefits.