严寒地区CRTSⅡ型无砟轨道板温度特性研究

Research on the Temperature Features of CRTS Ⅱ Ballastless Track Slab in Severe Cold Region

研究目的:应用数值模拟分析方法,针对在严寒地区,夏、冬两季典型天气条件下,由于气温、太阳辐射、空气对流等显著变化引起的高速铁路CRTSⅡ型无砟轨道板的瞬态温度场、温度应力及由其导致的板端翘曲、结构层间离缝、道床开裂等温度作用病害,对其形成机理进行研究。研究结论:(1)在夏季典型高温天气条件下,午后14时轨道板的表面温度最高可达42℃,温度梯度可达65℃/m,温度压应力可达10 MPa;(2)在冬季典型寒冷天气条件下,凌晨6时轨道板表面温度最低可达-39℃,温度梯度可达40℃/m,与夏季温度梯度方向相反,温度拉应力达到10 MPa;(3)本研究阐明了严寒地区冬、夏两季极端天气条件下CRTSⅡ型轨道板的温度特性作用机理,可为此种轨道板在严寒地区高速铁路中的应用提供参考。

Research purposes： Because radiation, and air convection, in severe of the noticeable changes of temperature, including air temperature, solar cold regions with FEM, the formation mechanism of damages of CRTS II ballastless track slab by thermal effects, such as slab end warps, open joints of structure layers, cracks of roadbed and so on, are studied. Research conclusions ： （ 1 ） In summer 14 h/PM, the temperature of the track slab surface is the highest with 42 ℃. The temperature gradient peak is 65℃/m, and the temperature compress peak is 10 MPa. （2） In winter 6 h/AM, the temperature of the track slab is the lowest with - 39 ℃, and it is synchronous change with the air temperature. The temperature gradient peak is 40 ℃/m, and the direction of the gradient is opposite to the summer＇s temperature gradient. The temperature tension stress peak is 10 MPa. （3）Based on above analysis, the damage mechanisms of the CRTS Ⅱ ballastless track slab were clarified that were under the winter and summer extreme weather conditions in severe cold region, and provided reference of the application of this kind of track slab in high - speed railway in severe cold region.