基于时序InSAR技术的京津高铁区域沉降稳定性评估

Regional subsidence stability evaluation along Jingjin high-speed railway based on MT-InSAR

高速铁路对轨道的平顺性及线下构筑物的稳定性有严格的要求,而铁路地理跨度大,采用定期的常规地面人工测量方法无法及时有效得到高速铁路沿线的形变,给线路的稳定性评价和列车的安全运营造成了潜在的隐患.本文以京津高速铁路永乐站至天津站区段为研究区域,利用时序差分雷达干涉测量技术,选用C波段雷达数据对沿线区域进行了形变监测,获得了该区域在2007-02—2010-07时间范围内的纵断面方向平均沉降速率曲线及沿线平均沉降变化率曲线;对比分析了沿线区域沉降变形规律,提出区域内差异性沉降是对线路稳定性影响较大的因素;并根据影响程度对线路进行了分级评估.该结论对于京津高铁的运营及维护具有重要参考意义和实用价值.

There are a series of strict limits for the high-level track regularity and the stability of sub- rail foundation of high-speed railway （HSR）, while the subsidence along HSR with a large geographic scope can＇t be acquired effectively in time by the traditional ground surveying methods, which make the stability evaluation of the rail difficult and threaten the safety of the running trains. Multi-temporal SAR interferometry （MT-InSAR） technique is adopted to monitor the subsidence along Jingjin HSR （Yongle-Tianjin segment） based on C-band SAR data from Feb. 2007 to Jul. 2010 in the study area. Average subsidence velocity of vertical section varying with time along HSR is extracted as well as the average subsidence rate of change curve. The characteristics of subsidence are comparatively analyzed and the results indicate that the subsidence difference value has a crucial influence on the stability of the lines. The subsidence classification is divided and the stability evaluation of the lines is put forward, which are significant and practical to operate and maintain the rail lines.