STUDIES ON DYNAMIC RESPONSE AND STABILITY OF ROADBED CONTAINING ICE UNDER TRAIN MOVING LOAD

Based on the soil temperature data from field observation and the geologic data, using the dynamic parameters of the frozen soil obtained from experiments, a calculating model for frozen soil roadbed is established combined with the soil dynamics theory and finite element method, and the stress and deformation situation of the roadbed containing ice under the train moving load are analyzed, comparing with that of the roadbed without ice. The results show that, as to the surface of the roadbed containing ice, the horizontal stress is higher than that of the roadbed without ice, and it is easier to crack, leading to the roadbed instability. The effect of the train moving load on the roadbed containing ice focus on the region within 12 m to each side of the roadbed and 15m beneath the surface of the roadbed. The more far the ice layer is apart from the roadbed surface, the more small the influence is on the roadbed stability. The roadbed will occur thaw subsidence instability as the ice layer thaws.