Comparison of dynamic lateral resistance of railway concrete, wooden and steel sleepers subjected to impact loading

摘要

This paper was devoted to investigating and comparing the dynamic lateral resistance (DLR) of various types of sleepers under lateral impact loading conditions. In this regard, a series of impact tests were conducted on concrete, wooden and steel sleepers in the laboratory, using an inventive pendulum loading test device (PLTD). In loading tests, different masses and triggering angles for the PLTD hammer, the impact load, inertia force and lateral displacement of sleepers were recorded by instrumenting the hammer and sleepers. Furthermore, in order to compare the ballast-sleeper interaction force diagrams in dynamic and static states of loading, a number of single tie (sleeper) push tests (STPTs) were accomplished in a similar circumstance. The laboratory results showed the insufficiency of steel sleeper in providing the DLR against impact loads in comparison with concrete and wooden sleepers. Moreover, the maximum DLR of concrete, wooden and steel sleepers were calculated as 12.2, 5.1 and 2.35 kN, which were considerably higher than their static lateral resistances (SLRs) of 6.2, 3.1 and 1.75 kN, respectively. Assuming an impact coefficient as the DLR/SLR ratio, the values of 1.98, 1.65 and 1.34 were attained for the mentioned sleepers, indicating a very good agreement with the value of 200% suggested by the American Railway Engineering and Maintenance-of-Way Association [AREMA. (2006). Manual for railway engineering. Lanham, MD: Author] for a concrete sleeper.