The influence of geotextile on the characteristics of railway subgrade mud pumping under cyclic loading

Abstract

The mud pumping beneath railways is both widespread and harmful and seriously affects the stability of railroad tracks and their operational safety. This paper presents a series of mud pumping tests, and analyses the influence of geotextile on the characteristics of saturated subgrade mud pumping. Our results show that the addition of geotextile between subgrade and gravel layers can significantly reduce accumulated axial strain by 40% to 76%, reduce residual excess pore water pressure by 33% to 92%, and reduce soil moisture content at the interface between the subgrade and gravel layers. However, we find that geotextile has no significant effect on soil dynamic stress. This suggests that the geotextile can act as a separator between the subgrade and gravel layers thus significantly reducing the thickness of an interlayer. Additionally, geotextile can also act as a filter and reduce the displacement caused by the migration of fine particles. In general, placing geotextile between the subgrade and gravel layers can mitigate railway subgrade mud pumping under cyclic loading, but with an increase in cyclic loading amplitude, the mitigating effectiveness of geotextile on mud pumping gradually weakens.