Rubber-Modified Asphalt Concrete for High-Speed Railway Roadbeds. High-Speed Rail IDEA Program:Final Rept. (Jan 2003-Feb 2005)

摘要

Interest in high-speed railway as an alternative means of transportation is steadily increasing around the world. However, high-speed trains produce track vibration and induced noise and ground vibration. Excessive track can cause damage to trains and tracks and reduce riding comfort for passengers. The ground vibrations induced by passing trains can also damage and disturb surrounding infrastructure (especially structures housing precision machines or instruments) and residents. This project studies one potential solution toward minimizing these vibrations using rubber-modified asphalt concrete (RMAC) as a material for high-speed railway roadbeds. This report presents the results of a two-dimensional finite-element simulation of a high-speed train foundation, laboratory tests on the influence of temperature and confining pressure on dynamic properties of RMAC, and a three-dimensional simulation of ground vibrations generated by high-speed trains. The simulated roadbeds were subjected to dynamic loading in several test scenarios, with RMAC and other traditional paving materials used as roadbed materials. The ground accelerations at designated points in these simulations were then monitored and compared to one another to determine the relative effectiveness in vibration attenuation. From these parametric studies RMAC has the potential to be more effective than currently-used paving materials (ballast, concrete and conventional asphalt concrete) in damping out vibrations from dynamic loading. Implications for field applications are also discussed. The results of laboratory tests show that RMAC as a higher damping ratio and stiffness than conventional AC and can maintain these desired properties for vibration attenuation in a wide variety of environments. The study also shows that some further laboratory tests, numerical simulation, and field tests are needed before the technique is used in the field.