Abstract
In order to understand the load environment of the ballast and tie, Transportation Technology Center, Inc. (TTCI), in cooperation with the University of Kentucky, used matrix based tactile surface sensors (MBTSS) to study the pressure distribution at the ballast-tie interface. MBTSS technology allows the loads generated from individual ballast particle contact points to be measured using a fine-scale pressure matrix. This research was conducted to characterize the ballast-tie peak pressures and contact areas over a range of ballast surface conditions. The highly nonuniform ballast-tie interface pressures measured were significantly higher than those currently used in North American design practice.