高原铁路运营振动荷载对冻土路基长期性能影响研究OA

Appropriate vibration mitigation measures were selected and evaluated to ensure the long-term operational safety of frozen soil subgrades in high-plateau railways and to clarify the influence mechanisms of operational vibration loads on their thermal stability,mechanical properties,and settlement deformation.This paper selected typical cross-sections of a rock-filled ventilated embankment in continuous permafrost regions and a conventional earth-filled embankment in island-shaped permafrost regions.A one-year field monitoring program was conducted to record vibration parameters,ground temperature,and settlement.Combined with laboratory tests,this paper analyzed the effects of vibration loading and the vibration mitigation and thermal stabilization performance of riprap layers,thermal drains(thermosyphons),and elastic cushion layers.The results show that:the dominant frequency of the vibration load ranges from 20 to 60 Hz,with a base vibration attenuation rate of 60%-70%.The island-shaped permafrost exhibits higher thermal sensitivity,with a ground temperature increase of up to 161.54%at a depth of 5 m.After 2 million vibration cycles,the compressive strength and cohesion of the soil decrease by 33.33%and 32.06%,respectively.This study clarifies the influence patterns of vibration loads and the applicability of various vibration mitigation measures,providing theoretical support and technical guidance for the stable operation of railway subgrades in permafrost regions.