Experimental and Numerical Study on Cyclic Loading of Railway Subgrade

This paper explicates the cyclic behaviour of soft clay railway subgrade, which is prone to mud pumping using laboratory experiments. Actual field conditions are applied on the soil samples using the dynamic triaxial apparatus to simulate the railway subgrades subjected to different train loads and speeds. The objective of this paper is to serve the reader with a rigorous understanding about the different aspects of cyclic behaviour of soil such as the generation of excess pore water pressure, cyclic axial strain development and effect of drainage on mud pumping through these laboratory experiments. For instance, the mechanism and mitigation of mud pumping are still being queried. Therefore, an endeavour to understand the mechanism of mud pumping and its mitigation is also given through this research. Evidently, the dynamic triaxial test results can be exploited to crystallize the understanding in the mechanism of mud pumping and its mitigation. Finite element modelling was done to investigate the effectiveness of prefabricated vertical drains in mitigating mud pumping in railways.