研究目的:本文利用无缝道岔稳定性公式和有限元方法对高原大日温差某车站无缝道岔的稳定性和力学性能进行理论计算,分析在年温差70 ℃左右、日温差40 ℃左右局部温度骤变的高原环境下铺设跨区间无缝线路的可能性,并对该车站及两端区间轨道进行跨区间无缝线路设计。采用胶冻结接头的方式消灭道岔和缓冲区有缝钢轨接头,在西藏地区第一次铺设桥上无缝道岔,一站两区间实现了跨区间无缝线路。通过一年时间在线监测和安全运营,积累了大量高原大日温差跨区间无缝线路可靠数据和运营经验。
研究结论:(1)验证了在年温差70 ℃左右、日温差40 ℃左右局部温度骤变的高原环境下铺设跨区间无缝线路是可行的;(2)胶冻结接头作为跨区间无缝线路钢轨连接方式是可行的,可为既有非无缝线路无缝化提供又一个技术方向;(3)在大日差局部温度骤变的高原环境下,跨区间无缝线路养护关键是无缝道岔,一定要注意道岔的轨道几何形位状态和尖轨、心轨的位移,出现不良状态时及时加强养护。

Research purposes:This paper calculated the stability and mechanical properties of the seamless turnout in the large daily temperature difference environment of the plateau with stability formula and the finite element method, analyzed the possibility of the laying of trans-section CWR in the plateau environment with an annual temperature difference of about 70 ℃ and the daily temperature difference of about 40 ℃, and designed trans-section CWR of the station and the tracks at both ends. By using the glue joints to eliminate the turnout and buffer rail joints, the seamless turnout on the bridge was laid for the first time in Tibet, and trans-section CWR between one station and two sections was realized. Through online monitoring and safe operation for more than a year, a large number of reliable data and operation experience of trans-section CWR with large daily temperature difference of the plateau were accumulated.
Research conclusions:(1) It proves that it is feasible to lay trans-section CWR in a plateau environment with an annual temperature difference of about 70 ℃ and a daily temperature difference of about 40 ℃.(2)The glue freezing joint is feasible as the rail connection mode of CWR, which can provide another technical direction for the seamless non-seamless line. (3) In the plateau environment of large daily local temperature change, the key to CWR maintenance is seamless turnout.It is necessary to pay attention to the track geometric position state of the turnout and the displacement of the sharp track and the heart track, and strengthen the maintenance in time when the bad state occurs.