【摘要】 膨胀土路基遇水膨胀引起的隆起变形病害已日渐凸显。当其隆起变形超出规范要求时，会直接影响高速列车行车安全。因此，对膨胀性路基的动力与变形特性展开研究具有重大现实意义。利用ABAQUS软件建立车辆-轨道-路基三维数值模型，通过模拟列车在膨胀土路基的实际运动过程，分析地下水上升作用下路基隆起变形引起的轨道不平顺性对路基动力特性的影响。研究表明：路基局部膨胀产生隆起变形后，竖向动应力和竖向动变形峰值均有明显增大，这会加剧路基疲劳破坏；轨道板造成的应力集中效应沿深度方向逐渐消失，且膨胀条件下会加剧竖向动应力响应；路基膨胀后会加剧动应力衰减，在干燥和浸水膨胀条件下，线路中心沿深度方向到基床底层底面处的竖向动应力分别衰减34.4%,42.5%。更多还原

【Abstract】 The swelling deformation of expansive soil subgrade caused by water swelling is becoming more and more obvious. When the heave deformation exceeds the standard requirement, it will directly affect the running safety of high-speed train. Therefore, it is of great practical significance to study the dynamic and deformation characteristics of expansive subgrade. A three-dimensional numerical model of vehicle-track-subgrade is established by using ABAQUS, and the actual train movement process on expansive soil subgrade is simulated, the influence of track irregularity caused by subgrade uplift deformation on subgrade dynamic and deformation is analyzed. The results show that the peak value of the vertical dynamic stress and the vertical dynamic displacement increase obviously after the local swelling deformation, which will aggravate the fatigue failure of the subgrade, and the stress concentration effect caused by the track slab disappears gradually along the depth. Under the condition of expansion, the response of vertical dynamic stress will be intensified, and the attenuation of dynamic stress will be intensified when the roadbed is immersed in water, the vertical dynamic stress from the line center along the depth direction to the bottom of the foundation bed decreases by 34.4%, 42.5% respectively.更多还原