目前大多数梁轨相互作用研究中并未考虑加载历史的影响,本文推导了考虑加载历史的线路纵向阻力表达式,与梁轨相对位移的微分方程联立,迭代求解钢轨纵向力和墩台水平力,计算结果更贴近实际情况。以高速铁路简支梁桥、连续梁桥和独塔斜拉桥为算例,采用考虑加载历史的荷载步法计算挠曲力和制动力,并与影响线及逐跨加载法进行对比。分析在梁体温度变形基础上各纵向力的计算方法,并与数值相加的结果进行比较。研究表明,逐跨加载法误差较大,影响线法计算钢轨纵向力结果虽偏安全,但其计算出的墩顶水平力比实际结果小10%~40%;通过单独计算钢轨纵向力并数值相加来检算钢轨时,应考虑伸缩力或制动力系数为-1时的情况;检算墩台时采用数值相加法有时会比实际结果小40%。
At present most of the beam-track interaction studies do not consider the influence of loading-history . In this paper the longitudinal resistance expression of track considering the loading-history was derived . By combining the beam-track differential equation , the longitudinal force of track and horizontal force of pier were solved by iteration and the calculation results were closer to the actual situation . Taking the simply-supported beam ,continuous beam and cable-stayed bridges of high-speed railways as examples , the step-by-step loading method inclusive of the loading-history was used to calculate the bending force and braking force , and was compared with the influence line and span-by-span loading . The calculation method of a variety of longitudinal forces was analyzed on the basis of the beam temperature deformation , and compared with the simple sum of them .Studies have shown as follows :The error of the method of span-by-span loading is comparatively large ;by using the influence line method , although the longitudinal force of track is inclined to safety , the calculated horizontal force on the pier top is 10% to 40% smaller than the actual values ;w hen only the longitudinal forces of rails are calculated and added together to verify examine the rails , the case should be considered w hen the expansion factor and braking force coefficient each being -1 ;w hen checking piers with the numerical addition method , the results are sometimes 40% smaller than actualities .