列车移动荷载在地基中引起的主应力轴旋转

利用移动荷载作用下地基的应力解答,计算列车移动荷载在弹性半空间地基内产生的动应力.根据计算土单元与列车的相对位置,将动应力曲线分为3个阶段,分别对这3个阶段的土单元应力路径和主应力轴旋转进行分析.在每一个循环中,土单元应力路径变化规律和主应力轴旋转规律与单个轮轴荷载引起的主应力轴旋转相似,但轮轴荷载的相互叠加使得应力路径变化和主应力轴旋转都更加复杂.单个轮轴荷载引起的主应力轴旋转一直为顺时针方向,而在一个循环中由列车引起的主应力轴旋转则会发生摆动,尤其是大主应力旋转到z轴附近时.

Principal stress axes rotation in ground induced by train moving load

The stresses in an elastic half-space induced by train moving load were computed based on the stress solution in the ground under moving load. The stress curve was divided to three stages according to the relative location of the soil element and the train. The stress path and the stress axes rotation of each stage were analyzed. Results show that the rule of stress path and principal stress axes rotation of soil element in one cycle is some similar to that induced by one wheel load. But the former is more complex due to the interaction of wheels. The stress axes rotation induced by one wheel is always clockwise, but that induced by train in one cycle swings especially when the maximum principal stress is near the z-axle.