桥墩温度梯度对高墩大跨桥上无砟轨道影响研究

Effects of Pier Temperature Gradient on Ballastless Track of Long-span Bridge

由于太阳光的辐射,桥墩的向阳和背阳侧就会存在温差,当桥墩高度较大时,墩顶就会产生较大的纵横向位移,带动梁体、轨道板、钢轨偏移,产生桥上无缝线路附加力。为了研究桥墩纵向温度梯度作用下对无砟轨道中轨道部件的受力和变形的影响,基于梁轨相互作用原理,利用有限元方法,建立线-桥-墩一体化模型,计算结果表明:仅考虑桥墩纵向温度梯度荷载时钢轨会产生较大的附加力,且随着桥墩刚度的增加,钢轨附加力也会增加。当同时考虑梁体升温和纵向温度梯度时产生的钢轨附加力小于两者单独作用产生的附加力。无论是仅考虑桥墩纵向温度梯度,还是同时考虑梁体温升和温度梯度,凸台受力和树脂变形均不会发生较大变化。

Due to solar radiation, both sides of a bridge are subjected to different temperatures. Where the height of a pier is larger, the pier will experience a greater longitudinal displacement, forcing the beam body, the track slab and the rail to displace, generating additional stress on CWR on the bridge. In order to understand the law of force and deformation of the ballastless track under pier temperature gradient, a line-bridge-pier integration model of CWR is established based on the beam-track interaction principle and the finite element method. The results show that the additional stress on the rail increases with the increase of the piers stiffness in perspective of only the vertical temperature gradient of pier load. In consideration of both the beam heating and the vertical temperature gradient, the additional rail stress is less than that when the stress generated by beam heating or vertical temperature gradient is considered respectively. The boss stress and resin deformation are not changed greatly regardless of the only pier vertical temperature gradient, or both the beam heating and vertical temperature gradient.