为研究小阻力扣件布置方案对重载铁路连续梁桥上无缝线路纵向力分布规律的影响,采用一种经过验证的梁轨相互作用分析方法,建立考虑相邻多跨简支梁结构的30t轴重重载铁路(60+100+60)m连续梁桥一桥上无缝线路的一体化空间有限元模型。在此基础上,对多种小阻力扣件方案进行比选,探讨了扣件阻力、下部结构刚度、荷载模式、制动力率等设计参数的影响。研究结果表明:仅在连续梁范围内铺设小阻力扣件,可在保证钢轨应力和墩顶水平力均较小的同时减小钢轨断缝值;小阻力扣件纵向阻力取值对钢轨应力的影响可达11.2%;在连续梁范围内铺设小阻力扣件后,梁轨快速相对位移成为主要控制性指标,100m跨重载连续梁桥制动墩顶纵向刚度限值为3000kN/cm;荷载模式和制动力率对梁轨相对位移影响较大,建议通过试验进一步明确重载列车的制动力率取值。
In order to reveal the influence of the layout of small resistance fasteners on the distribution of longitudi- nal force loaded on the continuously-welded rail of continuous bridge of heavy haul railway, a recognized method to analyze the rail-bridge interaction is adopted, and a spatial integrated finite element model, which takes into con- sideration the adjacent multi-span simply-supported beams, is established to describe the continuously-welded rail of a (60 + 100 + 60)m continuous bridge of the heavy haul railway with an axle load of 30t. Afterwards, based on the comparison of some layout plans of small-resistance fasteners, tener resistance, substructure stiffness, loading mode and braking the influences of such design parameters as fas- force ratio are discussed. The results show that (1) when small-resistance fasteners are only laid on the continuous beam, the rail stress as well as the horizontal force at pier top is rather small, and the broken seam value of the rail can be reduced at the same time ; (2) the in- fluence of longitudinal resistance of small-resistance fasteners on the rail stress is up to 11.2% ; ( 3 ) when small- resistance fasteners are laid on the continuous bridge, the rapid displacement between the rail and the beam be- comes the main controlling index, and the longitudinal stiffness limit at the brake pier top of a 100m-span continu- ous bridge reaches 3 000 kN/cm; and (4) both the loading mode and the braking force ratio greatly influence the displacement between the rail and the beam, so that an accurate braking force ratio should be determined by tests.