新型大调整量板式无砟轨道结构受力特性

The Force Characteristics of the New Type Large-adjustment Prefabricated Slab Track Structure

研究目的:为解决高速铁路无砟轨道沉降问题,本文提出一种新型大调整量单元板式无砟轨道,该新型轨道可重复使用,单次最大可向上调整176 mm。基于有限元法,本文建立新型轨道结构静力学模型和车辆-轨道垂向耦合动力学模型,分析该轨道在不同支撑条件下结构内部受力情况、临时支撑条件下车辆限速值、调高后轨道的动力响应和温度作用下结构内部受力情况。研究结论:(1)临时支撑条件下,垫块数量由4块增至12块,轨道拉压应力逐渐变小,且最大钢轨垂向加速度随速度的提升而增加,建议临时支撑时选用12块垫块,列车通行速度不超过120 km/h;(2)在调高高度0~15 cm且整体升降温50℃条件下,自密实混凝土、轨道板、底座板最大拉应力分别为0.45 MPa、1.72 MPa、0.97 MPa;(3)轨道运营时,较正常轨道,轨道调高15 cm,动力响应无明显变化;(4)针对过渡段、复杂艰险山区等大沉降地区,本文研究可为无砟轨道的设计和施工提供指导。

Research purposes: In order to solve the settlement problem of high-speed railway prefabricated track, this paper proposes a new type large-adjustment prefabricated slab track, which can be used repeatedly and can be adjusted by 176 mm in a single time. By establishing a new type of track statics model and vehicle-track vertical coupling dynamics model, this paper analyzes the stress of the structure under different support condition, the speed limit of the vehicle under temporary support conditions, the dynamic response of the track and the stress of the structure under temperature after the height adjustment.Research conclusions:(1) Under the condition of temporary support, the number of blocks is increased from 4 to 12,the tension and compression stress of the track gradually decreases, and the maximum vertical acceleration of the rail increases with the increase of the speed. It is recommended to use 12 blocks for temporary support, and the speed limit is 120 km/h.(2) When the height is increased by 0 ~ 15 cm and the overall temperature rises and falls at 50℃, the maximum tensile stress of self-compacting concrete, the track slab, and the base plate are 0. 45 MPa, 1. 72 MPa, and 0. 97 MPa respectively.(3) When the track is in operation, compared with the normal track, there is no obvious change in the dynamic response after the track raised 15 cm.(4) For road-culvert transition sections, complex mountainous areas and other large settlement areas, this research can provide certain guidance for the design and construction of the prefabricated track.