Numerical simulation analysis of dynamic response characteristics of inclined bedrock reinforced embankment under train loading

The central and western regions of China are predominantly mountainous, and in the constructed and future railways, a substantial proportion of embankments must be constructed on inclined strata in mountainous areas. However, the extant research on the dynamics of reinforced embankments on inclined strata is relatively limited. Therefore, based on the finite element numerical software, this paper establishes a numerical model of geotechnical reinforced embankments under inclined bedrock conditions, and compares and verifies the computational results with the existing experimental results, and then conducts an in-depth study and analysis of the dynamic response characteristics of the reinforced track embankment based on this model, focusing on the effects of cyclic load amplitude and the number of layers of geogrid on the dynamic response of the reinforced embankment. The results show that the dynamic response of the vertical cyclic displacement amplitude and peak velocity of the embankment shows a significant spatial non-uniform distribution, and their extreme values appears directly below the loading centre. The high-value areas of lateral displacement of the embankment are distributed at the bottom of the left slope and the top of the right slope. With the change of each parameter, the lateral peak displacement at the top of the right slope of the embankment increases more significantly, and it becomes the area with the largest lateral displacement. The limiting effect of geogrids on the amplitude of lateral displacement of the reinforced embankment is significant. With the gradual increase in the number of geogrid layers, the overall lateral displacement magnitude of the embankment decreases, and the area where the lateral displacement magnitude occurs shrinks and gradually moves upward. At the position of each layer of geogrid, the curve of the lateral displacement magnitude of the embankment versus the depth of the embankment shows an obvious valley value, and the depth of the valley is consistent with the location of the geogrid arrangement. When four layers of geogrid are set, the lateral displacement amplitude between geogrids and the lateral displacement amplitude at the top of the geogrids are similar, which can effectively play the role of geogrids in limiting the lateral displacement of the soil body.