兰新高速铁路军马场-民乐段地表形变监测及成因

Surface deformation monitoring and cause analysis of the section from the army horse ranch to Minle station of the Lanxin high-speed railway

以兰新高速铁路军马场-民乐路段为研究区域,利用SBAS-InSAR技术得到2014-2016年的路基形变速率与累积形变量,结合实测数据验证其可靠性,分析该段路基形变的时空特征,从自然因素与人为因素两方面分析路基形变的原因.结果表明,研究区域内大部分路基稳定,形变速率保持在-5~5 mm/a,但也存在形变较为严重的区域,其中以民乐县与山丹县交界处最为明显,累积沉降量达90 mm.气温和降水会导致路基的形变出现季节性变化,主要是由于湿陷性黄土稳定性差导致的路基沉降以及低温与高降水量导致的路基冻胀变化;灌溉渠、人口聚集区及施工活动均对该区域的沉降产生积极影响.

Taking the section of the army horse ranch to Minle station of the Lanxin high-speed railway as the research area,this paper obtained the deformation rate and cumulative deformation from 2014 to 2016 by using SBAS-InSAR technology,verified its reliability by combining with the measured data,and analyzed the temporal and spatial characteristics of subgrade deformation in this section.The causes of subgrade deformation were further analyzed from two aspects,i.e.natural and human factors.The results showed that most of the subgrade in this section of the Lanxin high speed railway was stable,and the deformation rate remained at -5 to 5 mm/a,but there were also areas with serious deformation,of whicht he junction of Minle and Shandan County was the most obvious,and the cumulative settlement could reach 90 mm.Temperature and precipitation factors would lead to seasonal changes in subgrade deformation,mainly due to the subgrade settlement being caused by the poor stability of collapsible loess,and the subgrade frost heave caused by low temperature and high precipitation;irrigation canals,population gathering areas and construction activities all had a positive impact on the settlement of the area.