摘要: |
Railroads require continuous supplies of crushed stone for use as ballast to maintain tracks. Over time and with repeated loading from rail traffic, the ballast becomes progressively fouled which inhibits drainage and degrades ballast strength and stability. This can lead to slow orders and maintenance actions and potentially derailments. A need exists for one or more inexpensive and efficient means for railroad personnel to identify and characterize the type and degree of fouling so an appropriate course of action can be identified. Kansas University (KU) has conducted research characterizing the relationships between strength, permeability, resistivity, and fouling. Distinct relationships have been observed between the type and amount of fouling and the permeability and resistivity. KU has also used a number of field instruments for a variety of geotechnical field investigations. It is proposed that a series of field tests including dynamic cone penetrometer, lightweight deflectometer, Wenner resistivity, image/video measurement, and other methods be used to characterize fouling, followed by excavation and fouling determination. The testing will be conducted on track in service and may also be conducted on artificial sections constructed at KU. Based on the results of the testing, recommendations will be developed for the use of the field instruments for characterization of fouling. |