| Brief Description of Research Project |
The first objective of this project is to develop a method to measure the pressure distribution and magnitude as well as contact area at the ballast-tie interface under heavy haul, Class I type loading. Ballast degradation at this interface has been observed to greatly contribute to overall ballast fouling and track quality deterioration. It has been hypothesized that the contact area at the ballast-tie interface may only be 5 to 10 percent of the tie's surface area. It is well established that ballast fouling, especially under the tie, contributes to premature, differential track settlement and increased maintenance. Developing a means to measure the pressures and contact area at the ballast-tie interface will allow a quantitative assessment of various factors affecting ballast life underneath the tie. These factors may include ballast type, ballast gradation, tie type, cross-section, and material, as well as the presence of "under tie" elastic pads, among others. Initial steps will include the measurement of aggregate (average) pressures under the tie and, determining repeatability of results and consistency between ties. A Matrix Based Tactile Surface Sensor system will be used to measure the peak pressures and pressure distribution (contact area) at the ballast-tie interface. Once a method of testing has been developed, initial research can begin on the factors that may influence pressure distribution at the interface. A second objective of this project is to perform a preliminary systematic/life‐cycle analysis of track bed upgrade to determine the relative performances of the 200 plus miles of track bed containing Enhanced Support on the BNSF Transcon Double‐Track capacity Improvement Project from southern Kansas to Amarillo, Texas. Primary interests are the subsequent Track Surfacing requirements and maintenance of Surface Quality Index geometric features relative to the conventional track sections, (will require substantial review of subsequent track geometry (SQI) tests and evaluations and track maintenance requirements). |