移动荷载作用下土的力学分析

Mechanic analysis of soil under moving load

在有限元软件ANSYS中建立三维有限元模型,研究道路结构中土基层的应力分布规律;用移动的恒定荷载模拟理想情况下车辆与地面相互作用的情形,用移动的简谐荷载模拟不平整地面上的车辆行走状况,分别考察荷载和车速对结构应力、应变和位移的影响。结果表明:最大等效应力、最大压应力和位移与荷载均呈线性关系增加,而与车速呈二次关系减小;同荷载、同速度下,恒定荷载作用时的最大等效应力和竖向位移均比简谐荷载作用时大,而最大压应力却比简谐荷载作用时小。

The three dimensional finite element model is established using the software of ANSYS and the stress distribution of the soil in the road structure is studied. The interaction force between the vehicle and the smoothness pavement and that between the vehicle and the roughness pavement are simulated by a movable constant load and a movable harmonic load respectively. The influences of the magnitude and speed of the load on the distribution of stress, strain and displacement of the road structure are analyzed. The numerical results show that the maximum Von Mises stress, the maximum compressive stress and displacement increase linearly with the increment of the magnitude of the load but decrease quadratically with the increment of the speed of the load. With the same magnitude and speed of the load, the maximum Von Mises stress and vertical displacement under movable constant load is larger than those of movable harmonic load, while the maximum compressive stress under movable constant load is smaller than that of the movable harmonic load. 10 tabs, 19 figs, 8 refs.