Ballast Degradation Analysis By Image Analysis

Ballast degradation and ballast accumulated deformation happens for the cyclic loading while train passing, and is shown by ballast breakage abrasion on surface and sharp corners broken. Afterwards, the small particles and powders go into the void between ballast particles, inducing poor drainage performance, which causes the loss of serviceability. With the development of CT and 3D imaging technology, more and more scientists start to utilize the shape angle and surface texture to estimate ballast particle for identifying the deterioration degree of ballast bed and the guidance of maintenance.Ballast degradation macroscopically leads to ballast contamination and worse track quality, thus causing higher operation and maintenance cost. Microscopically, it manifests as ballast particle surface geometry and physical index akeration. To reveal the mechanism of ballast degradation, the Los Angeles abrasion test is conducted, and the 3D laser scanner is utilized for image index analysis before and after the test. During the test the geometrical parameter of ballast particles are changing, including volume, shape, and abrasion loss.The outcome demonstrates that the main abrasion loss results from angularity breakage, the maximum abrasion depth is between 4-9mm, and the average abrasion depth is within 1 mm. The abrasion loss increases with ballast particle size. The results are useful for ballast material standard, degradation evaluation and maintenance. Meanwhile, the ballast degradation degree is conformed, and the reliability and accuracy of image analysis is shown.