季节性冻土区铁路路基动力响应模拟

SIMULATION OF DYNAMIC RESPONSE OF RAILWAY SUBGRADE UNDER TRAIN LOAD IN SEASONALLY FROZEN REGION

为了研究列车荷载作用下季节冻土区铁路路基的动力响应规律,采用ABAQUS有限元软件建立京哈铁路路基模型,平衡初始地应力,并以此为基础,对单次列车荷载以及长期列车作用下的高铁路基进行动力响应数值模拟分析。结果表明,在单次列车、列车长期荷载作用下,对比不同时期路基的位移场、应力场变化情况,得出季节性冻土区夏季温度较高时,单次列车荷载下路基表面竖向位移、速度、加速度、应力值均大于冬季,在相同深度处各值的衰减程度也大于冬季;同一时期单次列车荷载与列车长期荷载分别作用下,单次列车荷载作用下的路基竖向位移与应力等值大于列车长期荷载作用下的结果。

In order to study the dynamic response rule of railway roadbed in season frozen area under train load, the model of Beijing-Harbin Railway line was built by the use of finite element software ABAQUS and initial geostress was equilibrated. A numerical simulation of the dynamic response of high- speed rail subgrade under the action of single train load and long-term load is carried out on this basis. The results show that the displacement field and stress field of Subgrade in different periods are compared under the condition of single train and long-term train load respectively, the conclusions were reached that when the summer temperature is high in seasonal frozen soil region, the vertical displacement, velocity, acceleration and stress of the subgrade surface are larger than the winter; the attenuation degree of each value is greater than that in winter at the same depth, the vertical displacement and stress of the subgrade under the single train load are higher than that under the long-term load when single train load and long-term load were acted respectively in the same period.